Assignment icse chemistry class 9th

 Prepared by Akhilesh tiwari 

SECTION - 1

1. Balance the following equations :
   1. CaCO₃ (s) +HCl (aq) → CaCl₂ (aq) + H₂O (l) + CO₂(g)
   2. Zn (S) + HCl (aq) → ZnCl₂ (aq) + H₂ (g)
   3. MnO₂ (s) + HCl (aq) → MnCl₂(aq) + H₂O (l) + Cl₂ (g)
   4. Na₂CO₃ (s) + H₂SO₄ (aq) → Na₂SO₄(aq) + H₂O (l) + CO₂ (g)
   5. Mg₃N₂(s) + H₂O (l) → Mg(OH)₂ (s) + NH₃(g)
   6. NH₃ (g) + O₂ (g) → N₂ (g) + H₂O (l)
   7. MgCl₂ (aq) + Na₂CO₃ (aq) → MgCO₃ (aq) + NaCl (aq)
   8. Pb3O4àPbO + O2
   9. P + HNO3à NO2 + H2O + H3PO4
   10. NO2 + H2O à HNO2 + HNO3
   11. PbO + NH3àPb + H2O + N2
2. Write the formulae and balance the following equation :
   1. Zinc + dil. Sulphuric acid → Zinc sulphate + hydrogen.
   2. Ammonium sulphate + calcium hydroxide → Calcium sulphate + ammonia + water.
   3. Lead dioxide + hydrochloric acid → Lead chloride + water + chlorine.
   4. Aluminum oxide + sulphuric acid → Aluminum sulphate + water.
   5. Iron + conc. Sulphuric acid → Iron sulphate + sulphur dioxide gas + water.
3. What is the valency of :
   1. Fluorine in CaF₂
   2. Sulphur in SF₆
   3. Phosphorous in PH₃
   4. Carbon in CH₄
   5. Nitrogen in the following compounds : N₂O₃ , N₂O₅ , NO₂ , NO.

SECTION - 2

1. What are the limitations of chemical equation ?
2. MNO₃ is a formula of a nitrate of a metal M. write down the formulae of :
   • Oxide of M
   • Nitride of M
   • Sulphate of M
   1. Explain the term ‘valency’ and ‘variable valency’.
   2. How are the elements with variable valiancy named ?
3. What do you understand by the term chemical formula ? What information is given by the formula NH3 ?
4. Define balanced and unbalanced equation .
5. Give the names of the following compounds :
   Cu2O, CuO , Hg2O, HgO, FeO, Fe2O3
6. What are the information conveyed by a chemical equation?