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.