MUSINGU HIGH SCHOOL

AUGUST HOLIDAY ASSIGNMENT

CHEMISTRY FORM ONE

1.State two reasons why water is a compound and not a mixture . 2mks

2. Give reasons for the following statement.

  1. Heating zinc (11) oxide results in a permanent change. 2mks
  1. Heating potassium manganate (vii) results in a permanent change. 1mk

3.Name

a). The three most abundant gases in air 1 1/2mks

b). The three gases which pollution in the atmosphere . 1 1/2mks

4.Define the following terms: 4mks

·  Element

·  Atom

·  Compound

·  Molecule

5. Write a word equation for the reaction between: 5mks.

  1. Sodium and chlorine
  2. Carbon and Oxygen
  3. Calcium and hydrochloric acid
  4. Nitric acid and calcium carbonate
  5. Sulphuric acid and potassium hydroxide

6. Write symbols for the following elements 3mks

a)  Silicon

b)  Neon

c)  Tin

d)  Mercury

e)  Gold

f)  Platinum

7. An unknown element ‘X ` burns in oxygen to form an oxide. The oxide dissolves in water and the resulting solution turns red litmus paper blue.

  1. State with a reason whether the element is a metal or a non- metal 2mks.
  2. Would you expect the element to be an electric conductor or not? Give a reason.2mks
  3. Give Two examples of amphoteric oxides and two examples of neutral oxides . 4mks

8. Identify the oxidizing and reducing agents in the following reactions 2mks.

  1. Iron (ii) oxide + carbon (ii) oxide ------àIron + carbon (iv) oxide
  2. Hydrogen + copper (ii) oxide ------à Copper + Water

9. Give 5 methods of laboratory preparation of oxygen and write their corresponding word equations. 5mks.

10. Carbon (iv) oxide does not support combustion . However, burning magnesium continues to burn in a gas jar containing carbon (iv) oxide.

a)  State two other observations made. 2mks

b)  Write a word equation for the reaction . Show that this is redox reaction . 2mks

c)  Arrange the following in order of reactivity starting with the most reactive to the least reactive. Potassium, iron , zinc, lead, sodium, gold, silver, aluminium. 2mks

11. a. What is a catalyst 1mk

b. State the use of the following apparatus in a chemistry laboratory .2mks

  1. Pipette
  2. Spatula

c) List two properties of gas considered when choosing the method of gas collection.2mks

12. Explain why ;

  1. A solution is always a mixture but not every mixture is a solution 2mks.
  2. All alkalis are bases but not all bases are alkalis .2mks.