THE UNITED REPUBLIC OF TANZANIA NATIONAL EXAMINATION COUNCIL

CHEMISTRY FTNA 2013

SECTION B

 (i) The apparatus used for grinding granular chemicals in the laboratory include:

1. Crucible and watch glass
2. Mortar and pestle
3. Pestle and pair of tongs 
4. Spatula and basin

 (ii)  The substances that can be used to extinguish fire are:

1. Carbon dioxide and sand
2. Carbon dioxide and sugar
3. Nitrogen and sand
4. Nitrogen and water

 (iii) Which of the following electronic configurations are of metals?

A. 2:8:1 and 2:5

B. 2:8:2 and 2:6

C. 2:8:3 and 2:8:8:7

D. 2:8:6 and 2:8:8:7

 (iv) When sugar is dissolved in water, a uniform mixture is formed. The resulting mixture is called a:

1. Solute
2. Solution
3. Solvent
4. Suspension

 (v) Flammable chemicals are those which:

1. Burn skin
2. Catch fire easily
3. Explode
4. Extinguish fire

 (vi) Which of the following can be classified as a renewable source of energy?

1. Biomass
2. Coal
3. Coke
4. Petroleum

 (vii) The part of Bunsen burner that controls the amount of air coming in is called:

1. Air hole
2.  Barrel
3.  Collar 
4.  Jet

 (vii) The part of Bunsen burner that controls the amount of air coming in is called:

1. Air hole
2.  Barrel
3.  Collar 
4.  Jet

 (ix) The simplest formula of a compound formed when combining 13g of aluminum and 17g of chlorine is:

1. AlCl
2. _Al2Cl
3. Al₃Cl₂
4. AlCl₃

 (x) The second step in the scientific procedure is:

1. Data collection and analysis
2. Data interpretation
3. Experimentation and observation
4. Hypothesis formation

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

3. (a) What do you understand by the following terms?

(i) Emperical Formula

(ii) Relative atomic mass

(b)      A certain compound K contains 15.8% carbon and 84.2% sulphur. The molar mass of K is 76g/mol. Determine its:

(i)       simplest formula ... ......

(ii)     molecular formula .........

4.(a) Define the following terms as applied in Chemistry:

(i)Flame

(ii)Bunsen burner

(iii)Laboratory

(b)      List four properties of each of the following:

(i)       A luminous flame

(ii)     A non-luminous flame

 Write the chemical formula for each of the following compounds:

(i)Sodium carbonate

(ii)Calcium nitrate

(iii)Ammonium chloride

5. Calculate the percentage by composition of the underlined elements in the following compounds: (i) Na2S04

(b)      Give the use of each of the following components which are found in the First Aid kit:

(i)       Plaster .........

(ii)     A pair of scissors (iii) Cotton wool ......... (iv) Gloves .........

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