Question

Complete the missing components/variables given as x and y in the following reactions: 

(a) Pb(NO₃)₂(aq) + 2Kl(aq) → PbI₂(x) + 2KNO₃(y) 

(b) Cu(s) + 2AgNO₃(aq) → Cu(NO₃)₂(aq) + x 

(c) Zn(s) + H₂SO₄(aq) → ZnSO₄(x) + H₂(y) 

(d) CaCO₃(s) CaO(s) + CO₂ (g)

Answer 1

(a) Pb(NO₃)₂(aq) + 2Kl(aq) → PbI₂(s) + 2KNO₃(aq) 

Hence, x is (s) and y is (aq) (s) means PbI₂ exists in solid state and (y) means that KNO₃ exists in aqueous/liquid state. 

(b) Cu(s) + 2AgNO₃(aq) → Cu(NO₃)₂(aq) + 2Ag(s) 

Hence, x is Ag(s) In the above reaction, Ag gets replaced by Cu. 

(c) Zn(s) + H₂SO₄(aq) → ZnSO₄(aq) + H₂(g)

Hence, x is (aq) and y is (g) (aq) means copper sulphate formed exists in aqueous state. (g) Means hydrogen gas is liberating. 

(d) CaCO₃(s) \(\overset{heat}\longrightarrow\)CaO(s) + CO₂ (g)

Hence x is heat 

When CaCO₃ is heated in the presence of oxygen, it forms calcium oxide (CaO) and carbon dioxide.