CLASS-10 WORKSHEET

CHEMICAL REACTIONS AND EQUATIONS

1. Give 5 examples each of physical and chemical changes that take place around us in our day to day life.

2. When a magnesium ribbon is burnt in air, what are the two observations that you make?

3. Write a balanced chemical equation to represent decomposition of lead nitrate on heating. What are brown fumes due to?

4. write the chemical formulae of:-

  (i) Barium chloride (ii) Sodium Sulphate (iii) Ammonium phosphate (iv) Calcium hydroxide

  (v) Aluminium carbonate (vi) Magnesium hydrogen carbonate (vii) Zinc sulphide

  (viii) copper (׀) chloride (ix) Potassium Bromide (x) Lead nitrate (xi) Iron ( ׀׀׀) oxide (xii) Sodium Oxide (xiii) Silver sulphide (xiv) Calcium Fluoride

5. Write the following in the form of balanced chemical equations:-

  (a) Calcium carbonate decomposes on heating to form calcium oxide and carbon – di – oxide.

  (b) When ammonium hydroxide is added to a solvent of iron (ll) Sulphate, a green ppt of iron (ll) hydroxide and ammonium Sulphate are formed.

  (c) When a nail of iron is added to a solution of copper Sulphate, iron (ll) Sulphate and copper metal are formed.

  (d) Zinc reacts with dil hydrochloric acid to form zinc chloride and hydrogen gas is liberated.

6. A chemical reaction which is both combination as well as exothermic, is used by us for white washing purposes. Write the equation for the same.

7. What is a decomposition reaction? Give 2 examples each of decomposition taking place due to heat, light and electricity.

8. How does a displacement reaction differ from a double displacement reaction? Give examples to explain.