CSEE Chemistry Paper 1 2022 — Past Paper & Online Quiz

1. 1 alama

Which of the following are the components needed to start a fire?

A. Match box, fire wood and kerosene

B. Match box, fire wood and oxygen

C. Oxygen, fuel and fire wood

D. Oxygen, heat and match box

E. Oxygen, fuel and heat

2. 1 alama

Why is a shiny stove made to glow in order to boil water in a fraction of time?

A. It has got low melting point.

B. It has got low boiling point.

C. It has got low specific heat capacity.

D. It has got high thermal conductivity.

E. It is a good absorber of heat.

5. 1 alama

Which energy source that can be reused after being exploited?

A. Combustible source.

B. Non-renewable source.

C. Renewable source.

D. Synthetic source.

E. Natural source.

6. 1 alama

Which one is the molecular formula for prop-1-ene?

A. C3H

B. CH3CCH

C. C3H4

D. HCH2CCH

E. CH3CH=CH2

7. 1 alama

Which of the following is not a component of the First Aid Kit?

A. Goggles

B. A pair of scissors

C. Knife

D. Gloves

E. Razor blade

3. 8 alamas

The rate of a chemical reaction is influenced by the presence of a catalyst. Refer to Table 1 below for experimental results.

Table 1
Time (s)	0	2	4	6	8	10
Mass loss (g)	110.20	110.10	110.00	108.50	107.20	107.20

(i) Increases colliding particles per time 1 alama

(a) How will you ensure that the rate of reaction is measured in this experiment? 4 alama

(a) How will you ensure that the temperature of the reaction is maintained constant throughout the experiment? 2 alama

(b) Why did the rate of reaction decrease as the reaction progressed? 4 alama

(ii) Favours endothermic reaction 1 alama

(b) Write the equation for the reaction. 2 alama

(c) Predict the rate of the reaction if zinc powder was used instead of granules. 4 alama

(iii) Increases the speed to reach equilibrium 1 alama

(c) Write the chemical equation for the reaction. 2 alama

(iv) Favours the forward product of exothermic reaction 1 alama

(d) What is the effect on the rate of reaction if zinc powder was used instead of granules? 2 alama

(a to ) Increases the rate of reaction 1 alama

(v) Favours the forward product of endothermic reaction 1 alama

Boresha ili kuona majibu ya mfano.

4. 5 alamas

A certain compound with the molecular mass of 28 was analyzed and found to be composed of 0.6 g of carbon and 0.1 g of hydrogen. (a) (b)

(a) Work out its empirical formula and molecular formula. 3 alama

(a) Work out its empirical formula and molecular formula. 1 alama

(b) Classify the compound to its homologous series. 1 alama

(b) Classify the compound to its homologous series. 2 alama

(c) In terms of the rate of reaction, what happens if zinc powder was used instead of granules. Give a reason. 3 alama

Boresha ili kuona majibu ya mfano.

8. 8 alamas

Table 2 Water Sample | Volume of Soap Solution ( cm 3 ) | E | 0.2 | | F | 3.7 | | G | |

Table 2
Water Sample	Volume of Soap Solution ( cm 3 )
E	0.2
F	3.7
G

(a) Identify from the list of substances, the components that are elements and compounds. 4 alama

(a) Identify two things other than the volume of water that must be kept constant for such data 2 alama

(b) Give the difference between an element and a mixture. 6 alama

(b) (ii) Give three causes of hardness of water. 3 alama

Boresha ili kuona majibu ya mfano.

9. 12 alamas

Consider the following substances: milk, copper, soap, steel, chlorine and sugar.

(a) Give four reasons. 15 alama

(a) Give the definition of a homogeneous mixture. (2m) 2 alama

(b) Identify four different substances from the list in (a) that can be used to form a homogeneous mixture. (4m) 4 alama

(c) Identify two substances from the list in (a) that are elements. (2m) 2 alama

(d) Suggest a method of separating any two substances in a homogeneous mixture you formed in (b). (4m) 4 alama

Boresha ili kuona majibu ya mfano.

10. 10 alamas

The number of electrons in a neutral atom of element X is 15. The mass number of one of its isotopes is 31. (a) Write the electronic configuration of element X. (b) Which group and period does element X belong to in the periodic table? (c) Write the formula for the oxide of element X. (Assume X forms an oxide). (d) State two reasons why element X is called a non-metal. (2x2=4m)

(a) Arrange the following in order of decreasing reactivity: Potassium, Aluminium, Copper, Hydrogen, Magnesium. 3 alama

(a) Write the electronic configuration of element X. 2 alama

(b) Which group and period does element X belong to in the periodic table? 2 alama

(b) Describe how a metal is extracted using reduction of its oxide with carbon. 7 alama

(c) Give four reasons why it is important to know the reactivity series of metals. 5 alama

(c) Write the formula for the oxide of element X. (Assume X forms an oxide). 2 alama

(d) State two reasons why element X is called a non-metal. 4 alama

Boresha ili kuona majibu ya mfano.

11. 15 alamas

Answer one question in this section. Explain six effects of water pollution in Tanzania.

(a) What happens when sulphur burns in air? 5 alama

(13) Explain six effects of water pollution in Tanzania. 15 alama

(b) Describe the reaction between dilute Sulphuric acid and Zinc granules. 5 alama

(c) In what ways is Hydrogen useful to man? 5 alama

Boresha ili kuona majibu ya mfano.

14. 15 alamas

Describe six ways that can be adopted by people in Tanzania to conserve the environment.

(a) Describe six ways that can be adopted by people in Tanzania to conserve water. 15 alama

(14) Describe six ways that can be adopted by people in Tanzania to conserve the environment. 15 alama

Boresha ili kuona majibu ya mfano.

Chemistry · Karatasi 1 · 2022

Chemistry · Karatasi 1 · 2022

Sehemu A

Sehemu B

Sehemu C

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