THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL OF TANZANIA

FORM TWO NATIONAL ASSESSMENT

032   CHEMISTRY

Duration: 2:30 Hours

INSTRUCTIONS. 

1. This paper consists of sections A and B with a total of ten (10) questions.
2. Answer all questions in spaces provided.
3. All writing must be in blue or black ink except drawing which must be in pencil.
4. Calculators, cellular phones and any unauthorized materials are not allowed in the examination room.
5. Write your Examination Number at the top right corner of every page.
6. The following atomic masses may be used; H =1, N =14, O = 16, S = 32, Ca = 40

SECTION A (20 Marks)

Answer all questions in this section.

1. For each of the items (i) –(x), choose the correct answer from the among the given alternatives and write its letter in the box provide.

(i) What is the best way of keeping a clean test tube after use?

1. Keeping it in water
2. Keeping it on a test tube holder
3. Keeping it in a basin for test tubes
4. Keeping it on a test tube rack.

(ii) Which one of the following does not involve the processes of urban water treatment and purification?

1. Sedimentation
2. Distillation
3. Filtration
4. Chlorination.

(iii) Why hydrogen gas is not a constituent of air?

1. Because of being water soluble
2. Because of being denser than air
3. Because of being very light
4. Because of being highly flammable.

(iv) Which is the suitable alternative heat source to be used in absence of Bunsen Burner?

1. Torch and spirit burner
2. Torch and kerosene stove
3. Kerosene stove and spirit burner
4. Firewood and torch.

(v) Which group and period does the element with 11 electrons belong?

1. Group I and period 3
2. Group II and period 1
3. Group I and period 1
4. Group II and period 3.

(vi) What happens when substance A reacts with substance B to form a new substance C?

1. Substance A and B are said to have formed a solution
2. Substance A and B are said to have undergone a physical change.
3. Substance A and B are said to have undergone a chemical change.
4. Substance A and B are said to have undergone a dissolution.

(vii) Which components make fire triangle?

1. Oxygen, fuel and heat
2. Oxygen, nitrogen and heat
3. Oxygen, fuel and carbon dioxide
4. Oxygen, heat and hydrogen.

(viii) Which state is involved when drying wet clothes?

1. Liquid to solid
2. Solid to gas
3. Gas to liquid
4. Liquid to gas.

(ix) Which net charge exists in radicals?

1. Zero
2. Positive or negative
3. Neutral
4. Positive and negative.

(x) Why Non – luminous flame is the most applicable flame for heating purposes?

1. It is very nosy
2. It has no soot.
3. It is very hot
4. It has air holes open