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