THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL OF TANZANIA

CERTIFICATE OF SECONDARY EDUCATION EXAMINATION

032/1 CHEMISTRY 1

(For Both School and Private Candidates)

Time: 3 Hours Year: 2022

Instructions

1. This paper consists of sections A, B and C with a total of fourteen (14) questions.
2. Answer all questions in sections A and B and one (1) question from section C.
3. Section A and C carry fifteen (15) marks each and section B carries seventy (70) marks.
4. Non - programmable calculators may be used.
5. Cellular phones and any unauthorised materials are not allowed in the examination room.
6. Write your Examination Number on every page of your answer booklet(s).
7. The following constants may be used.

• Atomic masses: H = l, C = 12, N =14, O =16, Na =23.
• Avogadro's number 6.02 x 10²³ GMV at s.t.p 22.4 dm³ .
• 1 Faraday = 96,500 coulombs.
• 1 litre I= 1m³ = 1000 cm³.

SECTION A (15 Marks)

Answer all questions in this section.

l. For each of the items (i) - (x), choose the correct answer from the given alternatives and write its letter beside the item number in the answer booklet provided.

(i) Which is a chemical property of water?

1. It is a very good solvent.
2. It is neither acidic nor basic.
3. It has higher surface tension.
4. It can exist in three states of matter.
5. It expands when it freezes

(ii) What is the maximum number of electrons in the innermost shell of atoms?

1. 3
2. 1
3. 4
4. 2
5. 8

(iii) What feature is essential for a good fuel?

1. High speed of continuous energy supply.
2. High energy value supplied.
3. Low carbon dioxide supplied.
4. High carbon dioxide production.
5. High content of non-combustible material.

(iv) What conclusion can be drawn from the random movement of pollen grains suspended in air?

1. Matter is lighter in nature.
2. Matter is solid in nature.
3. Matter is particulate in nature.
4. Matter is gaseous in nature.
5. Matter is wave in nature.

(v) Which energy source that can be reused after being exploited?

1. Combustible source.
2. Non-renewable source.
3. Renewable source.
4. Synthetic source.
5. Natural source.

(vi) Which one is the molecular formula for prop-I -ene?

1. C₃H₅
2. CH₃CCH
3. C₃H₄
4. HCH₂CCH
5. CH₃CHCH₂

(vii) Which of the following is not a component of the First Aid Kit?

1. Goggles
2. A pair of scissors
3. Knife
4. Gloves
5. Razor blade

(viii) Which element is oxidised in the following reaction?

2FeSO₄ +CI₂ +H₂SO₄ → Fe(SO₄)₃+ 2HCl.

1. Chlorine
2. Hydrogen
3. Oxygen
4. Sulphur
5. Iron

(ix) Which of the following are the components needed to start fire?

1. Match box, fire wood and kerosene
2. Match box, fire wood and oxygen
3. Oxygen, fuel and fire wood
4. Oxygen, heat and match box
5. Oxygen, fuel and heat

(x) Why is nitrogen formed first during the fractional distillation of air?

1. It has got high boiling point.
2. It has got low density.
3. It has got low melting point.
4. It has got high density.
5. It has got low boiling point.

THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL OF TANZANIA

CERTIFICATE OF SECONDARY EDUCATION EXAMINATION

032/1 CHEMISTRY 1

(For Both School and Private Candidates)

Time: 3 Hours Year : 2021

Instructions

l. This paper consists of sections A, B and C with a total of fourteen (14) questions.

2. Answer all questions in sections A and B and one (1) question from section C.

3. Sections A and C carry fifteen (15) marks each and section B carries seventy (70) marks.

4. Cellular phones and any unauthorised materials are not allowed in the examination room.

5. Write your Examination Number on every page of your answer booklet(s).

6. The following constants may be used.

Atomic masses: H = 1, O =16, C =12, N = 14, Na =23, Ca = 40, Cl = 35.5, Pb= 207.

Avogadro's number =6.02 x 1023 GMV at s. t. p 22.4 dm³ .

1 Faraday = 96,500 coulombs.

Standard pressure = 760 mm Hg.

Standard temperature = 273 K.

I litre 1 dm³ 1000 cm³

SECTION A ( 15 Marks)

Answer all questions in this section.

l. For each of the items (i) — (x), choose the correct answer from among the given alternatives and write its letter beside the item number in the answer booklet provided.

(i) Which among the following sets of materials can cause fire outbreak?

1. Oxygen, carbon dioxide and fuel
2. Oxygen, heat and fuel
3. Oxygen, heat and carbon dioxide
4. Oxygen, foam and fuel
5. Oxygen, heat and foam

(ii)What type of fire occurs in vapour air mixture over the surface of flammable liquids?

1. Class A        
2. Class B       
3. Class C
4. Class D 
5. Class E

(iii)Which one of the following processes is a chemical change?

1. Butter melts on warm toast
2. Water evaporates from the surface
3. Juice in a bottle freezes
4. Food scrap turns into compost
5. Wet cloth dries

(iv) The simplest formula of a compound formed when combining 36 g of magnesium and 14 g of nitrogen is:

1. MgN
2. Mg₂N
3. Mg₃N₂ 
4. MgN₂
5. Mg₄N₂

(v)What is the IUPAC name for H₂S0₄ ?

1. Sulphuric acid
2. Sulphuric (VI) acid
3. Hydrogen sulphate
4. Dihydrogen sulphate
5. Hydrogen tetrasulphate

(vi)     What type of chemical reaction is represented by the equation  Zn(s) + 2HCl(aq)  + H₂(g)?

1. Displacement reaction
2. Combination reaction
3. Precipitation reaction
4. Decomposition reaction
5. Redox reaction

(vii)   What does the random movement of pollen grains suspended in air demonstrates?

1. Matter is lighter in nature.
2. Matter is solid in nature.
3. Matter is particulate in nature.
4. Matter is gaseous in nature. 
5. Matter is wave in nature.

(viii)"Organic matter is among the components of soil." Which role does it play?

1. Improving water infiltration of the soil.
2. Accelerating break down of organic matter.
3. Reserving nutrients thus providing soil fertility.
4. Converting of nitrogen into nitrates.
5. Providing a room for organic material such as nylons.

(ix) Which of the following sets represents isotopes of an element?

1.       Z, and
2.  Z, and
3.    Z, and
4.  Z, and
5.  Z, and

 (x)What is to be considered when choosing the best method to extract a particular metal from its ore?

1. The metal 's economic value.
2. Its availability in an area.
3. The metal's ore impurities.
4. How it reacts with other materials. 
5. The metal's shininess.

THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL OF TANZANIA

CERTIFICATE OF SECONDARY EDUCATION EXAMINATION

032/1 CHEMISTRY 1

(For Both School and Private Candidates)

Time: 3 Hours Year: 2020

Instructions

l. This paper consists of sections A, B and C with a total of fourteen (14) questions.

2.Answer all questions in sections A and B and one (1) question from section C.

3.Sections A and C carry fifteen (15) marks each and section B carries seventy (70) marks.

4.Cellular phones and any unauthorised materials are not allowed in the examination room.

5.Write your Examination Number on every page of your answer booklet(s).

6.The following constants may be used.

Atomic masses: H =l, C= 12, N=14, O= 16, Na = 23, S = 32, ca = 40, Cl = 35.5, cu = 64 Zn 65. 

Avogadro's number 6.02 x 10²³ 

GM V at s.t.p = 22.4 dm³ .

I Faraday = 96,500 coulombs.

Standard pressure = 760 mm Hg.

Standard temperature= 273 K.

I litre= I dm³ 1000 cm³.

SECTION A (15 Marks)

Answer all questions in this section.

For each of the items (i) - (x), choose the correct answer from among the given alternatives and write its letter beside the item number in the answer booklet provided.

(i) Which of the following pairs constitute the best methods for treating and purifying water?

1. Chlorination and aeration
2. Chlorination and decantation
3. Chlorination and filtration
4. Chlorination and sedimentation
5. Chlorination and distillation

(ii)A good fuel is the one which has

1. high speed of continuous energy supply.
2. high energy value supplied.
3. low carbon dioxide supplied.
4. high carbon dioxide production.
5. high content of non-combustible material.

(iii) A rapid chemical reaction that releases energy in form of light and heat is called 

1.  combustion.
2.  decomposition.
3.  displacement. 
4.  neutralization.
5.  precipitation.

(iv)Which one is the molecular formula for prop-I-yne?

1. C₃H₆ 
2.  CH₃CCH
3.  C₃H₄ 
4.  HCH₂CCH 
5.  CH₃CHCH₂

(v)Which of the following is not a component of the First Aid Kit?

1. Goggles 
2.  A pair of scissors
3.  Dropper 
4.  Gloves
5.  Razor blade

(vi)Which of the following is the correct sequence of the last two steps you should follow during the scientific procedure?

1. Hypothesis formulation and conclusion
2. Observation and problem identification
3. Experimentation and conclusion
4. Problem identification and hypothesis formulation
5.  Interpretation of data and conclusion.

(vii)Consider the following reagents:

1. H₂O₂
2. H₂O
3. MnO₄
4. .MnO₂

Which reagents are involved in the preparation of oxygen gas in the laboratory?

1. I and 2
2. 3 and 4
3. CI and 3
4. 2 and 3
5. I and 4

(viii)Why oxygen differs from other gases?

1. It neither burns nor support combustion.
2. It supports combustion but does not burn.
3. It burns but does not support combustion.
4. It burns and supports combustion.
5. It explodes and support combustion.

(ix)What is the best way of preparing hydrogen gas in the laboratory?

1. By reacting strong metals and dilute acids.
2. By reacting metals and acids.
3. By reacting moderate metals and concentrated acids.
4. By reacting moderate metals and dilute acids. 
5. By reacting strong metals and strong acids.

(x)What volume of hydrogen gas will be produced when 1.3 g of zinc granules react completely with excess dilute sulphuric acid at s.t.p?

1. 130 cm³  
2.  224 cm³
3.  440 cm³ 
4.  220 cm³
5.  448 cm³

THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL OF TANZANIA

CERTIFICATE OF SECONDARY EDUCATION EXAMINATION

032/1 CHEMISTRY 1

(For Both School and Private Candidates)

Time: 3 Hours Thursday, 07^th November 2019 a.m.

Instructions

1. This paper consists of sections A, B and C with a total of fourteen (14) questions.
2. Answer all questions in sections A and B and one (1) question from section C.
3. Cellular phones and any unauthorised materials are not allowed in the examination room.
4. Write your Examination Number on every page of your answer booklet(s).
5. The following constants may be used.

Atomic masses: H 1, O- 16, N- 14, S = 32, Zn - 65, Cl -35.5, cu - 64.

Avogadros number= 6.02 x 10²³

GMV at s.t.p =22.4 dm³ .

1 Faraday= 96,500 coulombs.

Standard pressure = 760 mm Hg. Standard temperature 273 K.

1 litre =1 dm³ =1000 cm 3.

SECTION A (15 Marks)

Answer all questions in this section.

1. For each of the items (i) — (x), choose the correct answer from among the given alternatives and write its letter beside the item number in the answer booklet provided.

(i) "Water is referred to as the universal solvent". What does this mean?

1. Water is neither acidic nor basic as compared to other liquids.
2. Water exists in three states of matter than any other liquids.
3. Water dissolves both organic and inorganic solutes.
4. Water is used more domestically than any other liquids.
5. Water dissolves more substances than any other known liquids.

(ii) When methane undergoes substitutional reaction with excess chlorine, what is the final product?

1. Chloromethane
2. Dichloromethane 
3. Trichloromethane 
4. Tetrachloromethane 
5. Monochloromethane

(iii)  Why is hydrogen gas collected over water and by upward delivery method?

1. It is insoluble in water and less denser than air.
2. It is soluble in water and denser than air.
3. It is insoluble in water and denser than air.
4. It is soluble in water and less denser than air.
5. It is soluble in both water and air.

(iv) Consider the following fuels which are used for different purposes:

1. Coal
2. Fire wood
3. Petrol
4. Charcoal.

Which fuels originate from fossils?

1. 1 and 3
2. 1 and 4
3. 2 and 4
4. 2 and 3
5. 1 and 2

(v) The following are the uses of chromatography except:

1. to analyse blood in crime scenes.
2. to detect different fibres.
3. to detect water pollution.
4. to bleach dye/colour.
5. to test purity of organic substances.

(vi)  What is the proper set of apparatus would you use to grind granules of a solid substance into fine powder in the laboratory?

1. Pestle and filter funnel   
2. Separating funnel and mortar
3. Pestle and filter paper                  
4. Pestle and mortar
5. Thistle funnel and mortar

(vii) Oxygen gas can be produced in a large scale by:

1. condensation of air.
2. condensation of liquefied air.
3. liquefaction of steam.
4. Fractional distillation of liquefied air.
5. evaporation of liquefied air.

(viii)  Which of the following sets of processes uses a gas that ignites with a "pop" sound when a lighted splint is passed through it?

1. Balloon filling, welding and diving 
2. Hardening oil, balloon filling and welding
3. Hardening oil, balloon filling and diving
4. Fueling rocket, diving and welding
5. Balloon filling, fueling rocket and diving

(ix) Which statement is the most correct about chemistry laboratory?

1. Is a special room designed for conducting chemical tests.
2. Is a special room designed for science practicals.
3. Is a special room designed for keeping apparatuses. 
4. Is a special room where data analysis is carried out.
5. Is a special room where students learn chemistry.

(x) Which role does the organic matter play in the soil?

1. Improving water infiltration of the soil.
2. Accelerating break down of organic matter.
3. Reserving nutrients thus providing soil fertility.
4. Converting nitrogen into nitrates.
5. Providing a room for organic material such as nylons.

THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL OF TANZANIA CERTIFICATE OF SECONDARY EDUCATION EXAMINATION 

032/1 CHEMISTRY 1

(For Both School and Private Candidates)

 Time: 3 Hours Thursday, 08^th November 2018 a.m.

Instructions

1. This paper consists of sections A, B and C with a total of thirteen (13) questions.
2. Answer all questions in this paper.
3. Calculators, cellular phones and any unauthorized materials are not allowed in the examination room.
4. Write your Examination Number on every page of your answer booklet(s).
5. The following constants may be used. Atomic masses:

 H 1, C = 12, 0=16, N = 14, Cu = 64,  Pb = 108. vogadros number = 6.02 x 10²³.

GMV at s.t.p = 22.4 dm³.

1 Faraday = 96,500 coulombs.

Standard pressure = 760 mm Hg.

Standard temperature = 273 K.

1 litre = 1 dm³ = 1000 cm³.

SECTION A (20 Marks) 

Answer all questions in this section.

1. For each of the items (i) (x), choose the correct answer from the given alternatives and write its letter beside the item number.

 (i) Which of the following is an agricultural chemical products made by the application of chemistry?

1. Drugs 
2. Pesticides 
3. Clothes 
4. Yeasts 
5. Cement.

 (ii) A current of 0.2 A was passed through an electrolyte for 16 minutes and 40 seconds. What is the quantity of electricity produced in coulombs?

1.  2000 C  
2. 1000 C 
3.  200 C 
4.  0.20 C 
5.  7686 C.

(iii) Substance X liberates chlorine gas from acidified potassium chloride. The behaviour of X is described as:

1.  an oxidising agent    
2.  an oxidising and reducing agent
3.  catalyst   
4.  a reducing agent
5.  bleaching agent.

(iv) Which carbonate is the most stable to heat?

1.  Calcium carbonate   
2.  Copper (II) carbonate
3.  Lead (II) carbonate 
4.  Zinc carbonate 
5. .Iron (II) carbonate.

(v)  Aluminium does not react with water and does not corrode much in air because

1.  it is below hydrogen in the reactivity series
2.  it forms a stable carbonate which prevents reactions
3.  the metal is covered with a protective coating of an oxide 
4.  aluminium ions have positive charges
5.  it is very stable.

(vi) Which of the following compounds does NOT belong to the alkenes homologous series?

1.  C₂H₄ 
2.  C₃H₆  
3.  C₄H ₈ 
4.  C₅H₁₀ 
5.  C₆H ₁₄.

(vii) In the following equilibrium equation, 2S0_2(g) +O_2(g)  2S0₃ The forward reaction is exothermic. Which change would increase the production of sulphur trioxide at equilibrium?

1.  Increasing temperature
2.  Decreasing temperature
3.  Decreasing sulphur trioxide concentration 
4. Decreasing pressure 
5. Adding a catalyst.

(viii) When a burning fuel produces blue color it means there is

1. adequate supply of oxygen with production of soot.
2. inadequate supply of oxygen without production of soot. 
3. inadequate supply of oxygen with production of soot.
4.  adequate supply of oxygen with production of less heat.
5.  adequate supply of oxygen with production of more heat.

(ix)  Which of the following equations represents the combustion of methane with the products collected at 120^oC?

1.  CH4(l) +2O2(g) ?CO2(g) + 2H2O(l)
2.  CH4(g) +2O2(l) ?CO2(s) + 2H2O(l)
3.  CH4(g) +2O2(g) ?CO2(g) + 2H2O(g)
4.  CH4(l) +2O2(l) ?CO2(l) + 2H2O(g)
5.  CH4(l) +2O2(g) ?CO2(g) + 2H2O(g)

   (x) Which of these can be reduced when heated with carbon?

1.  Aluminium  
2. Calcium carbonate
3. Iron (III) oxide 
4. Magnesium oxide 
5.  Sodium oxide.

THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL CERTIFICATE OF SECONDARY EDUCATION EXAMINATION

032/1              CHEMISTRY 1

(For Both School and Private Candidates)

Time: 3 Hours     Thursday, 02^ndNovember 2017 a.m.

 Instructions

1.  This paper consists of sections A, B and C with a total of thirteen (13) questions.
2. Answer all questions in this paper.
3. Calculators, cellular phones and any unauthorised materials are not allowed in the examination room.
4. Write your Examination Number on every page of your answer booklet(s).
5. The following constants may be used:

Atomic masses: 

H = 1,   C = 12,    O = 16,    S = 32,    Ca = 40,    Fe = 56,    Cu = 64,    Zn = 65.

   Avogadro’s number = 6.02 x 103 ²³.

GMV at s.t.p. = 22.4 dm .

1 Faraday = 96,500 coulombs.

Standard pressure = 760 mm Hg.

Standard temperature = 273 K. 1 litre = 1 dm³ = 1000 cm³. 

           SECTION A (20 Marks) 

Answer all questions in this section.

1.  For each of the items (i) - (x), choose the correct answer among the given alternatives and write its letter beside the item number in the answer booklet provided.

 (i)  Which of the following sets of elements is arranged in order of increasing electronegativity?

1.  Chlorine, fluorine, nitrogen, oxygen, carbon
2.  Fluorine, chlorine, oxygen, nitrogen, carbon
3.  Carbon, nitrogen, oxygen, chlorine, fluorine 
4. Nitrogen, oxygen, carbon, fluorine, chlorine
5.  Fluorine, nitrogen, oxygen, chlorine, carbon.

(ii) Which type of a fire is associated with electrical equipment.

1.  Class E 
2.  Class C 
3.  Class F 
4. Class B 
5.  Class A.

(iii)   Which of the following is the electronic configuration of an element Y found in period 3 and group II of the periodic table?

1.  2:8 
2.  2:8:2    
3.  2:6
4. 2:8:8:2   
5. 2:8:4 

(iv) Technicians prefer to use blue flame in welding because 

1. it is bright and non-sooty 
2. it is light and non-sooty.
3.  it is very hot and large.
4. it is very hot and non-sooty.
5.  it is not expensive.

(v) Which method could be used to separate the products in the following equation?

1.  Chromatography
2. Crystallisation 
3. Distillation 
4. Filtration 
5. Condensation.

(vi) The metal nitrate which will NOT give a metal oxide on heating is

1.  calcium nitrate 
2. silver nitrate 
3. lead nitrate 
4. copper nitrate 
5. zinc nitrate.

(vii)  Which of the following compounds does NOT belong to the alkane homologous series?

1.    C2H 4    
2.  CH4    
3. C4H 10     
4.  C3H 8              
5. C5H 12.

(viii) Which of the following is NOT among the composition of air?

1. Noble gases 
2. Carbon dioxide 
3. Nitrogen 
4. Hydrogen 
5. Water vapour.

(ix)   Chlorine ion, Cl^- differs from chlorine atom because it has       

1.   more protons. 
2.  less protons. 
3.  more electrons. 
4.  less electrons. 
5.  more neutrons.

(x) Which of the following pairs of compounds can be used in the preparation of calcium sulphate?

1. Calcium carbonate and sodium sulphate
2. Calcium chloride and ammonium sulphate
3. Calcium hydroxide and barium sulphate 
4. Calcium nitrate and lead (II) sulphate 
5. Calcium chloride and barium sulphate. 

THE UNITED REPUBLIC OF TANZANIA

NATIONAL EXAMINATIONS COUNCIL CERTIFICATE OF SECONDARY EDUCATION EXAMINATION.

032/1 CHEMISTRY 1

(For Both school and Private Candidates)

Time: 3Hours Friday, 04  ^th   November 2016 a.m

Instructions.

1. This paper consists of section A, B and C

2. Answer all questions in this paper

3. Calculators and cellular phones are not  allowed in examination room.

4. Write your Examination Number on every page of your answer booklet(s)

5. The following constants may be used.

Atomic masses: C = 12, O = 16, Mg = 24, Al = 26, S = 32,

Cl = 35.5, Mn = 55, Fe = 56, Cu = 63.5,

Avogadro ’s number = 6.02 _x_  10  ²³  ,

GMV at s.t.p = 22.4dm  ³ 

1Faraday = 96,500 coulombs

Standard pressure = 760mm Hg.

Standard temperature = 273 K,

1 litre = 1dm  ³  = 1000cm  ³ 

SECTION A:

1. For each of the items (i) – (x), choose the correct answer from the given alternatives and write its letter beside the item number in the answer booklet provided.

(i) Which of the following is True about the following equilibrium?

1. Water molecules have stopped changing into ions.

2. Water molecules have all changed into ions

3. Concentrations of water molecules and ions are equal

4. Concentrations of water molecules and ions are constant

5. Water molecules are moving slow.

(ii) The property of metal to be drawn into wires is called?

1. Conductivity

2. Malleability

3. Ductility

4. Decorating

5. Expansion.

(iii) If a steady current of 2 amperes was passed through an aqueous solution of iron (II) sulphate for 15 minutes, the mass of iron deposited at the cathode will be.

1. 30g.

2. 56g.

3. 0.54g.

4. 28g.

5. 0.52g.

(iv) What will happen when zinc is placed in aqueous copper (II) sulphate?

1. Copper atoms are oxidized

2. Zinc atoms are oxidized

3. Copper ions are oxidized

4. Zinc ions are oxidized

5. Sulphur atoms are oxidized.

(v) Which of the following pair of gas can be prepared in the laboratory and collected over water?

1. Oxygen and Ammonia

2. Hydrogen and Hydrochloric acid

3. Hydrogen and Ammonia

4. Oxygen and Hydrogen chloride

(vi) Two substances are allotropes of carbon if

1. Both reduce heated iron (II) oxide to iron

2. Have different crystalline structure

3. Have equal masses

4. Have equal shape

5. Have the same arrangement of atoms

(vii) The apparatus suitable for measuring specific volumes of liquids is called?

1. Burette

2. Volmetric flask

3. Pipette

4. Measuring cylinder

5. Graduated beaker

(viii) The reaction  represents which among the following reactions.

1. Synthesis

2. Precipitation

3. Neutralization

4. Displacement

5. Decomposition

(ix) The occurrence of two or more compounds with the same molecular formula but different molecular structures is known as.

1. Amphoterism

2. Isomerism

3. Allotropy

4. Polymorphism

5. Isotopy

(x) Which of the following sets of symbols represent isotopes of a single element?

1.  ¹⁶  ₈  X,  ¹⁷  ₈  X,  ¹⁸  ₈  X

2.  ¹⁶  ₈  Z,  ¹⁷  ₈  Z,  ¹⁸  ₈  X

3.  ¹⁶  ₇  P,  ¹⁶  ₈  P,  ¹⁶  ₉  P

4.  ¹⁶  ₇  K,  ¹⁷  ₈  K,  ¹⁸  ₉  K

5.  ¹⁶  ₇  U,  ¹⁶  ₈  U,  ¹⁸  ₁₀  U

(i)                 The mass number of a carbon atom that contains six protons, eight neutrons, and six electrons is

1.   6   
2.  14  
3.  8
4. 12
5.  20.

(ii)               How many moles of oxygen are required for the complete combustion of 2.2 g of C3H 8 to form carbon dioxide and water?

1.  0.050 moles 
2. 0.15 moles   
3. 0.25 moles
4.   0.50 moles  
5.  0.025 moles.

(iii)             In the graph below, curve 1 was obtained from the decomposition of 100 cm³ of 1.0M hydrogen peroxide solution catalysed by manganese (IV) oxide, 2H2O 2?2H            2O+O    2 .

Which alteration/change to the original experimental conditions would produce curve 2?

1.  Lowering the temperature
2.  Using less manganese IV oxide
3. Increasing the temperature
4. Adding some 0.1 M H2O   
5.  Using a different catalyst.

(iv)              How long must a current of 4.00 A be applied to a solution of Cu ₍²_a⁺_q) to produce 2.0 grams of copper metal?

1.  2.4x10²s
2. 1.5x10³s
3. 7.6x10²s
4. 3.8x10²s
5. 12x10⁴s               

(v)                Which of the following hydrocarbons does NOT belong to the same homologous series as the others?

1.   CH₄ B
2.    C3H 8      
3.   ^C4^H₁₀      
4. C6H 12        
5.  C2H 12.

(vi)              A solution of pH 1.6 is best described as

1. weak acid  
2. strong base   
3. weak base
4.  strong acid
5.  neutral solution.

(vii)            Which among the following equations correctly shows the reaction between chlorine gas and water?

1. Cl 2(g) + H 2 O (l) ? Cl 2(g)
2. 2Cl 2(g) + 2H 2 O (l) ? 4Cl + O 2(g) + 2H 2(g)
3. Cl 2(g) + H 2 O (l) ? HCl (aq) + HOCL (aq)
4. 2Cl 2(g) + 2H 2 O (l) ? 2HOCl 2(aq) + H 2(aq)
5. 2Cl 2(g) + 3H 2 O (l) ? Cl 2(g) + 2H 3 O + .

(viii)          Hygroscopic and deliquescent substances can be used as

1.  oxidising agents  
2.  drying agents   
3. reducing agent
4.  weak electrolytes  
5.   catalyst.

(ix)              Which among the following pair of substances are allotropes?

1. H 2 O and H 2 O 2
2. 12 C and 14 C
3. P 4 and P 8
4. H 2 and 2H +
5. H + and H 3 O.

(x)                Water can be obtained from a solution of common salt by

1.  evaporation 
2.  simple distillation 
3. filtration
4. condensation 
5.  fractional distillation.

THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL

CERTIFICATE OF SECONDARY EDUCATION EXAMINATION 

032/1  CHEMISTRY 1

 (For Both School and Private Candidates)

Time: 3 Hours  Thursday, 06^th November 2014 p.m.

 Instructions

1. This paper consists of sections A, B and C.
2. Answer all questions in this paper.
3.  Calculators and cellular phones are not allowed in the examination room.
4.  Write your Examination Number on every page of your answer booklet(s).
5.  The following constants may be used.

 Atomic masses:

 H = 1, C = 12, N = 14, Na = 23, S = 32, O = 16, Al = 26, Cl = 35.5 Ca = 40, Mn = 55, Fe = 56, K = 39.

 Avogadro’s number = 6.02 x 10²³.

 GMV at s.t.p. = 22.4 dm³.

 1 faraday = 96,500 coulombs.

 Standard pressure = 760 mm Hg.

 Standard temperature = 273 K.

 1 litre = 1 dm³ = 1000 cm³.

SECTION A (20 Marks)

Answer all questions in this section.

1. For each of the items (i) – (x), choose the correct answer from the given alternatives and write its letter beside the item number in the answer booklet provided.

(i)  An element in the periodic table with atomic number 18 belongs to which of the following?

1. Group I and period I.
2. Group O and period III.
3. Group III and period III.
4. Group V and period IV.
5. Group VII and period IV.

(ii)  The ionic equation when aqueous ammonium chloride reacts with sodium hydroxide solution is represented as:

1. 2NH+4(aq) + 2Cl-(aq)à 2NH3(g) + Cl2(g) + H2(g)
2. NH+4(aq) + OH-(aq) à NH3(g) + H2O(l)
3. Na+(aq) + Cl-(aq) à NaCl(g)
4. H+(aq) + OH-(aq) à H2O(l)
5. 2NH+4(aq) + 2Cl-(aq) à 2NH3(g) + 2HCl(g).

(iii)  The reason why white anhydrous copper (II) sulphate turns blue when exposed in atmosphere is that it,

1.   reacts with carbon dioxide.
2. reacts with oxygen
3. becomes dry.
4. absorbs water vapour.
5. decomposes.

 (iv)  Chemical change means;

1.   the change is reversible.
2. can easily be separated.
3. the change is complete.
4. new substance is produced.
5. produces no change of mass.

(v)  If a stead current of 2 amperes was passed through an aqueous solution of iron (II) sulphate for 15 minutes, then the mass of iron deposited at the cathode will be:

1. 54 g.
2. 56 g.
3. 0.54 g.
4. 28 g.
5. 0.52 g.

(vi)  10 cm³ of 0.4 M sodium hydroxide are added to 40 cm³ of 0.2 M hydrochloric acid. The resulting mixture will be

1. Neutral
2. Alkaline
3. Dilute
4. Acidic
5. Amphoteric

(vii)  The only metal which does not react with dilute hydrochloric acid is

1. Magnesium
2. Aluminum
3. Copper
4. Zinc
5. Sodium.

(viii)  Which of the following solutions is the most concentrated?

1. 50 g of calcium carbonate in 100 cm³ of water
2. 60 g of sodium chloride in 200 cm³ of water
3. 65 g of potassium nitrate in 100 cm³ of water
4. 120 g of potassium sulphate in 200 cm³ of water
5. 50 g of sodium hydroxide in 200 cm³ of water.

ix) Alcohols react with carboxylic acids to form a group of organic compounds called

1. alkynes
2. aldehydes
3. ethers
4. esters
5. alkanols.

(x) Which of the following statement is true about water gas?

1. It is poisonous.
2. Contains hydrogen.
3. Is the same as biogas.
4. Contains hydrogen and nitrogen.
5. Contains carbon monoxide and hydrogen.

 THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL

CERTIFICATE OF SECONDARY EDUCATION EXAMINATION 

032/1  CHEMISTRY 1

 (For Both School and Private Candidates) 

Time: 3 Hours  Thursday, 07^th November 2013 p.m.

 Instructions

1. This paper consists of sections A, B and C.
2.  Answer all questions in this paper.
3.  Calculators and cellular phones are not allowed in the examination room.
4.  Write your Examination Number on every page of your answer booklet(s).
5.  The following constants may be used.

 Atomic masses:

 H = 1, C = 12, O = 16, N = 14, Na = 23, Mg = 24, Al = 26, S = 32, Cl = 35.5, Ca = 40, Fe = 56, Cu = 64, Ag = 108.

 Avogadro’s number = 6.02 x 10²³. GMV at s.t.p. = 22.4 dm³.

 1 faraday = 96,500 coulombs.

 Standard pressure = 760 mm Hg.

 Standard temperature = 273 K.

 1 litre = 1 dm³ = 1000 cm³.

SECTION A (20 Marks)

Answer all questions in this section. 

1.  For each of the items (i) – (x), choose the correct answer from the given alternatives and write its letter beside the item number in the answer booklet provided.

 (i)  Which action should be taken immediately after concentrated sulphuric acid spilled on the skin?

1. Its should be rinsed off with large quantities of running water.
2. It should be neutralized with solid CaCO₃
3. It should be neutralized with concentrated NaOH.
4. The affected area should be wrapped tightly and shown to a medical health provider.
5. It should be neutralized with concentrated KOH.

 (ii)  In the titration of a monoprotic acid with a solution of sodium hydroxide of known concentration, what quantities will be equal at the equivalence point?

1. concentration of hydroxide solution and hydronium ions.
2. number of moles of hydroxide ions added and number of moles of hydronium ion initially present.
3. number of moles of hydroxide solution added and volume of acid solution initially present.
4. number of moles of hydroxide ion added and the number of moles of monoprotic acid initially present.
5. volume of sodium hydroxide solution added and volume of acid solution initially present.

 (iii)  The charge of one mole of electrons is represented by the term

1.   one ampere
2. one coulomb
3. one volt
4. one faraday E
5. one gram.

 (iv)  65.25 g sample of CuSO₄.5H₂O (M = 249.7) was dissolved in water to make 0.800 L of solution. What volume of this solution must be diluted with water to make 1.00 L of 0.100 M CuSO₄?

1.   3.27 ml
2. 383 ml
3. 209 ml
4. 65.25 ml
5. 306 ml.

 (v)  Consider the system at equilibrium: H₂O_(l) H₂O_(g) for which Which change(s) will increase the yield of H₂O_(g).

1. Increase in temperature
2. Increase in the volume of the container
3. Increase in temperature and volume of the container
4. Increasing surface area of oxygen
5. Increasing surface area of reactants.

 (vi)  As water is added to an acid, the acid becomes

1.   more acidic and its pH goes down
2. more acidic and its pH goes up
3. less acidic and its pH goes up
4. less acidic and its pH goes down
5. neutral and its pH becomes 7.

 (vii)  Three elements, X, Y and Z, are in the same period of the periodic table. The oxide of X is amphoteric, the oxide of Y is basic and the oxide of Z is acidic. Which of the following shows the elements arranged in order of increasing atomic number?

1.   X, Y, Z
2. Y, Z, Y
3. Z, X, Y
4. Y, X, Z
5. X, Z, Y.

 (viii)  Which of the following compounds contains only two elements?

1.   Magnesium hydroxide
2. Magnesium nitride
3. Magnesium phosphate
4. Magnesium sulphite
5. Magnesium sulphate.

 (ix)  An atom has 26 protons, 26 electrons and 30 neutrons. The atom has

1.   atomic number 26, mass number 52
2. atomic number 56, mass number 30
3. atomic number 30, mass number 82
4. atomic number 52, mass number 56
5. atomic number 26, mass number 56.

 (x)  The following equation is a propagation step in the chlorination of methane:

1. Cl₂ Cl^• ₊ Cl^•
2. CH^•₃ + Cl^• CH₃Cl
3. CH^•₃ + Cl₂ CH₃Cl + Cl^•
4. CH₄ + Cl^• CH₃Cl + H^•
5. CH^•₃ + Cl₂ Ch₂Cl + Cl^•.

THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL

CERTIFICATE OF SECONDARY EDUCATION EXAMINATION 

032/1  CHEMISTRY 1

 (For Both School and Private Candidates)

Time: 3 Hours  Thursday, 11^th October 2012 p.m.

 Instructions

1.  This paper consists of sections A, B and C.
2.  Answer all questions in this paper.
3.  Calculators and cellular phones are not allowed in the examination room.
4.  Write your Examination Number on every page of your answer booklet(s).
5.  The following constants may be used.

 Atomic masses:

 H = 1, C = 12, O = 16, N = 14, Na = 23, Mg = 24, Al = 26, S = 32, Cl = 35.5, Ca = 40, Mn = 55, Fe = 56, Cu = 64.

 Avogadro’s number = 6.02 x 10²³.

 GMV at s.t.p. = 22.4 dm³.

 1 Faraday = 96,500 coulombs.

 Standard pressure = 760 mm Hg.

 Standard temperature = 273 K.

 1 litre = 1 dm³ = 1000 cm³.

SECTION A (20 Marks)

Answer all questions in this section.

1. For each of the items (i) – (x), choose the correct answer from the given alternatives and write its letter beside the item number in the answer booklet provided.

(i)  Which one of the following sets of laboratory apparatus are used for measure volume?

1. Crucible, U-tube and volumetric flask
2. Test tubes, beakers and glass jar
3. Thistle funnel, separating funnel and beaker
4. Burette, pipette and measuring cylinder
5. Conical flask, test tube and measuring cylinder.

(ii)  The empirical formula of certain compound in CH₃. Its molar mass is 30 g. What will be its molecular formular?

1. CH₄
2. C₂H₄
3. C₂H₆
4. C₂H₈
5. C₄H₁₂

 (iii)  In order to produce the greatest amount of hydrogen in a short time, one gram of magnesium ribbon should react with

1. 10 cm³ of 0.5 M sulphuric acid
2. 40 cm³ of 0.5 M acetic acid solution
3. 40 cm³ of 0.5 M sulphuric acid solution
4. 20 cm³ of 1 M sulphuric acid solution
5. 20 cm³ of 1 M acetic acid solution.

(iv)  Fractional distillation process of a mixture of water and ethanol is possible because

1. water and ethanol have the same boiling point
2. water has lower boiling point than ethanol
3. ethanol has lower boiling point than water
4. water and ethanol form partially immiscible liquid solution
5. water and ethanol are immiscible liquids.

 (v)  Which of the following substances represent a group of acidic oxides?

1. Carbon dioxide, carbon monoxide and sulphur dioxide
2. Sulphur trioxide, nitrogen dioxide and nnitrogen monoxide
3. Carbon dioxide, sulphur dioxide and dinitrogen oxide
4. Sulphur trioxide, carbon dioxide and nitrogen dioxide
5. Carbon monoxide, nitrogen oxide and sulphur dioxide.
   

 (vi)  What will the molarity of a solution which contains 26.5 g of anhydrous sodium carbonate in 5 dm³ of solution?

1. 0.05 M
2. 0.25 M
3. 5.30 M
4. 0.025 M
5. 0.50 M

 (vii)  The Brownian movement is taken to be the evidence of the:

1. theory of association of water molecules
2. theory of ionization of electrolytes
3. theory of colloidal suspensions
4. kinetic theory of behavior of substances
5. Brownian theory.

 (viii)  One off the isotopes of an element X has an atomic number Z and a mass number A. What is the number of neutrons contained in the nucleus of the element X?

1. Z
2. A
3. A + Z
4. A – Z
5. Z – A

(ix)  C₂H₄Cl can be represented in different structures which are called

1. homologous series
2. isomers
3. structural formulae
4. identical structures
5. condensed structures.

(x)  _____ is the general term used to explain a mixture of different metals.

1. Alloy
2. Allotrope
3. Amphoteric
4. Amorphous 
5. Isotope.

THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL CERTIFICATE OF SECONDARY EDUCATION EXAMINATION 

(For School Candidates Only)

TIME: 3 Hours Thursday, 7^th  October 2010 p.m.

 Instructions

1. This paper consists of sections A, B and C.

2. Answer all questions in sections A and B, and two (2) questions from section C.

3. Calculators and cellular phones are not allowed in the examination room.

4. Write your Examination Number on every page of your answer booklet(s).

5. The following constants may be used:

Atomic masses: H = 1, O = 16, Na = 23, Mg = 24, C = 12

Cl = 35.5, K = 39, Pb = 207.

Avogadro’s number = 6.02 x 103 ²³.

GMV at s.t.p. = 22.4 dm .

1 Faraday = 96,500 coulombs.

Standard pressure = 760 mm Hg.

Standard temperature = 273 K.

1 litre = 1 dm³ = 1000 cm³.

.SECTION A (20 marks)

Answer all questions in this section.

1. For each of the items (i) ­ (x), choose the correct answer among the given alternatives and write its letter beside the item number in the answer booklet provided.

(i) 1.4 g of potassium hydroxide is dissolved in water to form 250 cm³ of solution. What is the molarity of this solution?

1.  0.01 M
2.  0.1 M
3.  1.4 M
4.  5.6 M
5.  6.0 M

(ii) In the blast furnace carbon monoxide is prepared by passing carbon dioxide over a red­hot coke. Carbon dioxide is

1.  an accelerator
2.  an oxidizing agent
3.  a reducing agent
4.  a catalyst
5.  oxidized.

(iii) A catalyst can be described as a substance 

1. that alters the rate of reaction
2.  that slows down the rate of reaction
3.  used in every reaction so as to speed up rate of reaction
4.  that starts and speeds up the rate of reaction
5.  that terminates chemical reaction.

(iv) A covalent bond is formed when

1.  a metal combines with a non­metal
2.  potassium and oxygen combine
3.  ammonia is formed
4.  two metals combine
5.  atom looses an electron.

(v) A solvent can be obtained from a solution by

1.  evaporation followed by decantation
2.  filtration and condensation
3.  evaporation and filtration
4.  evaporation and condensation
5.  crystallization followed by sublimation.

(vi) Aqueous sugar solution is a poor conductor of electricity because

1.  water and sugar are covalent compounds
2.  water is a non­electrolyte
3.  sugar is a non­electrolyte
4.  sugar is covalent when in liquid form
5.  sugar dissolves completely in water.

(vii) The process of giving away water of crystallization to the atmosphere by a chemical substance is called

1.  efflorescence
2.  deliquescence
3.  hygroscopic
4.  sublimation
5.  vapourisation.

(viii) Copper can be separated from a mixture of zinc and copper by adding to the mixture

1.  concentrated H2SO ₄
2.  dilute H2SO 4
3.  aqueous solution of ZnSO4
4.  concentrated HNO₃
5.  a catalyst.

(ix) Among the factors that determine the ions to be discharged at electrodes when salt solutions are electrolysed are their

1.  non metallic nature
2.  relative concentrations in the solution
3.  relative ionic masses
4.  electronic configuration
5.  position in the periodic table.

(x) The mass of sodium hydroxide contained in 25 cm³ of 0.1 M NaOH is

1.  0.5 gm
2. B 2.85 gm
3.  250 gm
4.  0.2 gm
5.  25 gm

(i)                 Which of the following is not among the instruments and chemicals used for First Aid? 

1. A Pair of scissors
2. Assorted bandages
3. Sterilized cotton wool
4.  Mosquito spray
5. Iodine tincture

(ii)               If 0.9 g of calcium metal is burnt in air, the mass of powder formed is

1. 1.14 g
2.  1.18 g
3. 1.12 g
4.  1.08 g
5. 1.26 g

(iii)             Domestic utensils made of iron do rust as a result of the presence of

1.  air and fire
2.   air and water
3. water and oil
4.  oil and fire
5.  air and oil.

(iv)              Which of the following statements about the hardness of water is not true?

1. Soft water readily forms lather with soap
2. Hard water does not readily form lather with soap
3. Permanent hardness of water is due to sulphates of calcium and magnesium
4.  Permanent hard water becomes soft on boiling
5. Calcium and magnesium hydrogen carbonates decompose on boiling.

(v)                Elements lose or gain electrons to form

1. isotopes
2. radicals
3.  molecules
4. ions
5.  allotropes

(vi)              An aqueous solution with pH 6 is

1. slightly acidic
2. strongly alkaline
3.  strongly neutral
4.  strongly acidic
5. slightly alkaline.

(vii)            The atmospheric effect of burning fuel such as wood and petrol oils is to

1. reduce oxygen gas
2.  produce clouds
3. add carbon dioxide gas
4. increase water vapour
5.  produce energy.

(viii)          A mixture of 50 cm³  of ethanol and 50 cm³ of pure water can be separated by

1.  solvent extraction
2. fractional distillation
3. simple distillation
4.  filtration
5.  decantation.

(ix)              The oxidation state of chlorine in sodium chlorate (NaClO3) is

1.  ­1
2. +2
3.  +5
4.  +3
5. 3.

(x)                When ethane (C2H 6) burns in air with a bright smoky flame the product(s) formed will be

1.  carbon dioxide gas
2.  carbon dioxide gas and water
3. water
4. water and oxygen gas
5. oxygen gas.