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.