Question

Complete the missing components/variables given as x and y in the following reactions (a) Pb(NO3) 2 (aq) + 2KI(aq) ⎯→ PbI2 (x) + 2KNO3(y) (b) Cu(s) + 2Ag NO3 (aq) ⎯→ Cu(NO3 )2 (aq) + x(s) (c) Zn(s) + H2SO4(aq) ⎯→ ZnSO4(x) + H2(y) (d) CaCO3(s) ⎯⎯⎯x → CaO(s) + CO2(g)

Answer 1

(a) Pb(NO3 )2 (aq) + 2KI (aq) ⇨ PbI2 (s) + 2KNO3 (a)
(b)Cu (s) + 2AgNO3 (aq) ⇨ Cu(NO3 )2 + Ag (s)
(c)Zn (s) + H2SO4 (aq) ⇨ ZnSO4 (aq) + H2 (g)
(d)CaCO3 + Heat ⇨ CaO (s) + CO2 (g)

Answer 2

Explanation:

The given balanced chemical reaction are :

(a) $Pb(NO_3)_2(aq)+2KI(aq)\rightarrow PbI_2(x)+2KNO_3(y)$

This reaction occurs when aqueous lead nitrate react with aqueous potassium iodide to give solid lead iodide and aqueous potassium nitrate.

So, in this reaction 'x' is solid (s) and 'y' is aqueous (aq)

Thus the given balanced chemical reaction will be,

$Pb(NO_3)_2(aq)+2KI(aq)\rightarrow PbI_2(s)+2KNO_3(aq)$

(b) $Cu(s)+2AgNO_3(aq)\rightarrow Cu(NO_3)_2(aq)+x(s)$

This reaction occurs when solid copper react with aqueous silver nitrate to give aqueous copper nitrate and solid silver.

So, in this reaction 'x' is silver (Ag)

Thus the given balanced chemical reaction will be,

$Cu(s)+2AgNO_3(aq)\rightarrow Cu(NO_3)_2(aq)+2Ag(s)$

(c) $Zn(s)+H_2SO_4(aq)\rightarrow ZnSO_4(x)+H_2(y)$

This reaction occurs when solid zinc react with aqueous sulfuric acid to give aqueous zinc sulfate and hydrogen as a gas.

So, in this reaction 'x' is aqueous (aq) and 'y' is gas (g)

Thus the given balanced chemical reaction will be,

$Zn(s)+H_2SO_4(aq)\rightarrow ZnSO_4(aq)+H_2(g)$

(d) $CaCO_3(s)+x\rightarrow CaO(s)+CO_2(g)$

This reaction occurs when solid calcium carbonate decomposes to give solid calcium oxide and carbon dioxide as a gas.

So, in this reaction 'x' is heat.

Thus the given balanced chemical reaction will be,

$CaCO_3(s)+\text{Heat}\rightarrow CaO(s)+CO_2(g)$