Class 10 Solutions Chemical Reactions And Equations

1.Complete and balance the following equations :
(a) NaOH + ………… —–> Na2S04 + H20
(b) Ca(OH)2 + ……….—–> CaC03 + H20
Solution :
(a) 2NaOH + H2SO4 —–> Na2SO4 + 2H2O
(b) Ca(OH)2 + CO2 —–> CaCO3 + H2O

2.Correct and balance the following equations :

1. Ca + H20 — > CaOH + H
2. N + H — > NH3

Solution :

1. Ca + 2H2O —–> Ca(OH)2 + H2
2. N2 + 3H2 —–> 2NH3

3.Write complete balanced equations for the following reactions :
(a) Calcium (solid) + Water (liquid) —–> Calcium hydroxide (solution) + Hydrogen (gas)
(b) Sulphur dioxide (gas) + Oxygen (gas) —–> Sulphur trioxide (gas)
Solution :
(a) Ca (s) + 2H2O(l) —–> Ca(OH)2(aq) + H2 (g)
(b) 2SO2(g) + O2 (g) —–> 2SO3(g)

4.

1. Na + O2 —–> Na2O
2. H2O2 —–> H2O + O2
3. Mg(OH)2+ HCl —–> MgCl2 + H2O.
4. Fe + O2 —–> Fe2O3
5. Al(OH)3 —–> Al2O3 + H2O
6. NH3+ CuO —–> Cu + N2 + H2O
7. Al2(SO4)3+ NaOH —–> Al(OH)3 + Na2SO4
8. HNO3+ Ca(OH)2 —–> Ca(NO3)2 + H2O
9. NaOH + H2SO4 —–> Na2SO4 + H2O
10. BaCl2+ H2SO4 —–> BaSO4 + HCl

Solution :

1. 4Na + O2 —–> 2Na2O
2. 2H2O2 —–> 2H2O + O2
3. Mg(OH)2+ 2HCl —–> MgCl2 + 2H2O.
4. 4Fe + 3O2 —–> 2Fe2O3
5. 2Al(OH)3 —–> Al2O3 + 3H2O
6. 2NH3+ 3CuO —–> 3Cu + N2 + 3H2O
7. Al2(SO4)3+ 6NaOH —–> 2Al(OH)3 + 3Na2SO4
8. 2HNO3+ Ca(OH)2 —–> Ca(NO3)2 + 2H2O
9. 2NaOH + H2SO4 —–> Na2SO4 + 2H2O
10. BaCl2+ H2SO4 —–> BaSO4 + 2HCl

5. (a) Give one example of a chemical reaction.
(b) State two characteristics of the chemical reaction which takes place when dilute sulphuric acid is poured over zinc granules.
(c) Give two characteristics of the chemical reaction which occurs on adding potassium iodide solution to lead nitrate solution.
Solution :
(a) Magnesium Ribbon is heated in the presence of air to form a white powder called magnesium oxide.
(b) When dilute sulphuric acid is poured over zinc granules

1. there will be a rise in temperature
2. evolution of hydrogen gas.

(c)

1. A yellow precipitate is formed.
2. There will be a change in color (from colourless to yellow).