THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL OF TANZANIA
FORM TWO NATIONAL ASSESSMENT

032 CHEMISTRY

Time: 2:30 HoursYear: 2020

Instructions

1. This paper consists of sections A and B with a total of ten (10) questions.

2. Answer all questions in the spaces provided.

3. Section A carries twenty (20) marks and section B carries eighty (80) marks.

4. All writing must be in black or blue ink except diagrams which must be in pencil.

5. Cellular phones and any unauthorised materials are not allowed in the assessment room.

6. Write your Assessment Number at the top right corner of every page.

7. The following atomic masses may be used: H = 1, N = 14, 0 = 16, S = 32, Ca = 40.

SECTION A (20 Marks)

Answer an questions in this section.

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

(i) The net charge inside the nucleus of an atom is contributed by

1. protons
2. neutrons
3. electrons
4. all nucleons.

(ii) Why oxygen as one of the components of air is unique? 

1. It support combustion.
2. It is a diatomic gas.
3. It forms the largest part of the air.
4. It has the largest density.

(iii) Which material is not involved in respiration? 

1. Carbon dioxide  
2. Nitrogen
3. Oxygen 
4. Water

(iv) Which element causes permanent hardness of water when combined with sulphate?

1. aluminium
2. magnesium
3. potassium
4. sodium.

(v) Carbon dioxide. Oxygen, Nitrogen and Hydrogen Sulphide are 

1. major components of air.
2. covalent compounds.
3. divalent gases.
4. ionic compounds.

(vi) Which common feature is associated with elements of the same group? 

1. Equal number of protons
2. Equal number of electrons
3. Equal number of valence electrons
4. Equal number of shells.

(vii) The oxidation state of metallic elements is always

1. negative
2. Neutral
3. positive
4. zero.

(viii) An isotope of Lead with atomic number of 82 and mass number of 207 has

1. 82 protons, 125 neutrons and 82 electrons. 
2. 25 protons, 82 neutrons and 125 electrons.
3. 82 protons, 207 neutrons and 125 electrons.
4. 207 protons, 207 electrons and 82 neutrons.

(ix) Which conditions are necessary for iron nails to rust?

1. oxygen and moisture
2. carbon and oxygen
3. carbon dioxide and oxygen
4. oxygen and nitrogen.

(x) Which decision should be made if the results of an experiment do not support the stated hypothesis?

1. To use the results as an idea for further testing.
2. To ignore the results and set a new experiment.
3. To repeat the experiment in the same way.
4. To identify a new problem.

THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATIONS COUNCIL OF TANZANIA
FORM TWO NATIONAL ASSESSMENT

032 CHEMISTRY

Time: 2:30 HoursYear: 2020

Instructions

1. This paper consists of sections A and B with a total of ten (10) questions.

2. Answer all questions in the spaces provided.

3. Section A carries twenty (20) marks and section B carries eighty (80) marks.

4. All writing must be in black or blue ink except diagrams which must be in pencil.

5. Cellular phones and any unauthorised materials are not allowed in the assessment room.

6. Write your Assessment Number at the top right corner of every page.

7. The following atomic masses may be used: H = 1, N = 14, 0 = 16, S = 32, Ca = 40.

SECTION A (20 Marks)

Answer an questions in this section.

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

(i) The net charge inside the nucleus of an atom is contributed by

1. protons
2. neutrons
3. electrons
4. all nucleons.

(ii) Why oxygen as one of the components of air is unique? 

1. It support combustion.
2. It is a diatomic gas.
3. It forms the largest part of the air.
4. It has the largest density.

(iii) Which material is not involved in respiration? 

1. Carbon dioxide  
2. Nitrogen
3. Oxygen 
4. Water

(iv) Which element causes permanent hardness of water when combined with sulphate?

1. aluminium
2. magnesium
3. potassium
4. sodium.

(v) Carbon dioxide. Oxygen, Nitrogen and Hydrogen Sulphide are 

1. major components of air.
2. covalent compounds.
3. divalent gases.
4. ionic compounds.

(vi) Which common feature is associated with elements of the same group? 

1. Equal number of protons
2. Equal number of electrons
3. Equal number of valence electrons
4. Equal number of shells.

(vii) The oxidation state of metallic elements is always

1. negative
2. Neutral
3. positive
4. zero.

(viii) An isotope of Lead with atomic number of 82 and mass number of 207 has

1. 82 protons, 125 neutrons and 82 electrons. 
2. 25 protons, 82 neutrons and 125 electrons.
3. 82 protons, 207 neutrons and 125 electrons.
4. 207 protons, 207 electrons and 82 neutrons.

(ix) Which conditions are necessary for iron nails to rust?

1. oxygen and moisture
2. carbon and oxygen
3. carbon dioxide and oxygen
4. oxygen and nitrogen.

(x) Which decision should be made if the results of an experiment do not support the stated hypothesis?

1. To use the results as an idea for further testing.
2. To ignore the results and set a new experiment.
3. To repeat the experiment in the same way.
4. To identify a new problem.