THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATION COUNCIL

CHEMISTRY FTNA 2018

(i) Chemistry is a branch of Science which deals with:

1. matter in relation to energy.
2. matter in relation to decomposition.
3. matter composition and its decomposition.
4.  properties of conservation of matter.

(ii) Which of the following are the states of matter?

1. Gas, liquid and mixture
2. Gas, liquid and solid
3. Element, compound and mixture
4. Element, mixture and gas.

(iii)Which of the following are the main components of a fire triangle?

1. Air, temperature and fire 
2. Oxygen, temperature and fuel
3.  Oxygen, heat and fuel
4. Oxygen, temperature and fire

(iv)The process of removing solid contaminants from water is known as:

1. water decantation.
2. water solidification.
3. water purification.
4. water sedimentation.

(v)How many zones are there in a non-luminous flame?

1. Four zones
2. Two zones
3. Three zones
4. Five zones

(vi)The process of coating iron or steel with zinc is known as:

1. zinc painting.
2. alloying.
3. tin plating.
4.  galvanization.

(vii)A certain element has atomic number W and mass number Y. The number of neutrons contained in its nucleus is:

1. W
2. W-Y
3. Y-W
4. Y+W

(viii)When a small amount of sugar is dissolved in a glass of water the mixture formed is:

1. heterogeneous. 
2. immiscible.
3.  suspension. 
4.  homogenous.

(ix)Fainting is a sudden loss of:

1. confidence. 
2. weight of the body. 
3.  water in the body. 
4.  consciousness.

(x)Why is fractional distillation of coal done?

1.  To remove oxygen in the atmosphere.
2. To remove volatile matter. 
3.  To add oxygen in the furnace.
4. To add volatile matter.

2. (a) Match each item in List A with a correct response in List B by writing its letter below the number of the corresponding item in the table provided.

(b) Fill in the blank spaces with the correct answer.

(i) A reaction that releases energy in the form of light and heat is called..........

(ii)A chemical process that occurs in steel and iron in the presence of air and water is known as..........

(iii)Oxygen, heat and fuel are the three components that make..........

(iv)Injuries that result from the body coming into contact with heat of harmful chemicals are called..........

(v)A solution which can dissolve no more solute at a given temperature is called . . . . . . . . . . .

SECTION B

3.(a) Indicate the corresponding meaning of the following warning signs.

(b) Give four importance of First Aid.

4.Draw and give one function of the following apparatus:

(b) By excluding a Bunsen burner, mention other three sources of heat that can be used in the laboratory.

(c) Why is a Bunsen burner the best heat source in the laboratory? Give three (3) reasons.

5. Define the following terms:

(i) Brownian motion

(ii) Compound

(b) Identify whether the following is a physical or chemical change: 

(i) Cutting aluminium foil into pieces 

(ii) Lighting a match .

(c) How can you separate the following mixtures? Briefly explain.

(i)Water and kerosene

(ii)Salt and water

(iii)Ethanol and water

6.(a) During preparation of Hydrogen gas by the reaction between dilute Hydrochloric acid and Zinc granules, the granules slowly dissolve in acid to form solution X. 

(i) Name solution X .........

(ii) Write the chemical formula of X . . . . . . 

(b) How can hydrogen gas be tested?

(c) Mention four (4) chemical properties of hydrogen gas.

(d) List three (3) uses of Hydrogen gas.

7. (a) (i) How many electrons and protons are present in oxygen element and aluminium element?

(ii) Write the electronic configuration of chlorine ion.

(b) Use the elements with chemical symbols: P, S and Cl to answer the following questions:

(i)Which elements is the most electronegative?

(ii)Mention the least electronegative element.

(iii)Which element has the largest atomic structure?

(c)Study the following table with elements lettered F, G, L, M and J, then answer the questions that follow:

(i)How many neutrons are present in element L?

(ii)Which group and period of the periodic table does element F belong?

(iii)Which element does not readily form compounds? Give a reason.

8.(a) Write four (4) sources of energy used for cooking in most Tanzanian societies.

(b) List four (4) characteristics of a good fuel.

(c) List two areas where scientific procedure can be applied.

9.Outline six common apparatus used in the laboratory preparation of oxygen gas using hydrogen peroxide.

(b) Outline four uses of oxygen in everyday life situation.

10.(a) Define the following terms:

(i)Valency

(ii)Oxidation state

(iii) Anion

(iv)Cation

(b) Calculate the oxidation state of the underlined elements in the following radicals:

(i) NH₄+

(ii) SO₄²⁺

(iii) CLO₃^-

(c) A compound consists of 40% carbon, 6.67% hydrogen and 53.33% oxygen. If its relative molecular mass is 60, calculate the following:

(i)Empirical formula

(ii)Molecular formula