A) 2HCl(aq) + Ba(OH)2(aq) → BaCl2(aq) + 2H2O(l) Ionic: Net ionic:

This set of questions covers writing ionic and net ionic equations for precipitation and neutralisation reactions, as well as balancing chemical equations. Below, each part is solved step-by-step.

Question a: Ionic and Net Ionic Equations for Neutralisation

Given equation: 2HCl(aq)+Ba(OH)2​(aq)→BaCl2​(aq)+2H2​O(l)

Ionic Equation

Break all strong electrolytes into ions: 2H+(aq)+2Cl−(aq)+Ba2+(aq)+2OH−(aq)→Ba2+(aq)+2Cl−(aq)+2H2​O(l)

Net Ionic Equation

Cancel spectator ions (Ba2+ and Cl−): 2H+(aq)+2OH−(aq)→2H2​O(l) Or simplified: H+(aq)+OH−(aq)→H2​O(l)

Question b: Ionic and Net Ionic Equations for Precipitation

Given equation: Pb(NO3​)2​(aq)+(NH4​)2​SO4​(aq)→PbSO4​(s)+2NH4​NO3​(aq)

Ionic Equation

Break all soluble salts into ions: Pb2+(aq)+2NO3−​(aq)+2NH4+​(aq)+SO42−​(aq)→PbSO4​(s)+2NH4+​(aq)+2NO3−​(aq)

Net Ionic Equation

Cancel spectator ions (NH4+​ and NO3−​): Pb2+(aq)+SO42−​(aq)→PbSO4​(s)

Question c: Ionic and Net Ionic Equations for Precipitation

Given equation: CuSO4​(aq)+2NaOH(aq)→Cu(OH)2​(s)+Na2​SO4​(aq)

Ionic Equation

Break all soluble salts into ions: Cu2+(aq)+SO42−​(aq)+2Na+(aq)+2OH−(aq)→Cu(OH)2​(s)+2Na+(aq)+SO42−​(aq)

Net Ionic Equation

Cancel spectator ions (Na+ and SO42−​): Cu2+(aq)+2OH−(aq)→Cu(OH)2​(s)

Question 7: Balancing Chemical Equations

i. PCl5(s) + H2O(l) → POCl3(l) + HCl(aq)

Unbalanced: PCl5​+H2​O→POCl3​+HCl

Balance Cl and H: PCl5​+H2​O→POCl3​+2HCl

ii. Cu(s) + HNO3(aq) → Cu(NO3)2(aq) + H2O(l) + NO(g)

Unbalanced: Cu+HNO3​→Cu(NO3​)2​+H2​O+NO

Balance: 3Cu+8HNO3​→3Cu(NO3​)2​+4H2​O+2NO

iii. (NH4)2Cr2O7(s) → Cr2O3(s) + N2(g) + H2O(l)

Unbalanced: (NH4​)2​Cr2​O7​→Cr2​O3​+N2​+H2​O

Balance: (NH4​)2​Cr2​O7​→Cr2​O3​+N2​+4H2​O

iv. KNO3 + H2CO3 → K2CO3 + HNO3

Unbalanced: KNO3​+H2​CO3​→K2​CO3​+HNO3​

Balance K: 2KNO3​+H2​CO3​→K2​CO3​+2HNO3​

Summary Table:

ReactionIonic EquationNet Ionic Equationa2H++2Cl−+Ba2++2OH−→Ba2++2Cl−+2H2​O2H++2OH−→2H2​ObPb2++2NO3−​+2NH4+​+SO42−​→PbSO4​+2NH4+​+2NO3−​Pb2++SO42−​→PbSO4​cCu2++SO42−​+2Na++2OH−→Cu(OH)2​+2Na++SO42−​Cu2++2OH−→Cu(OH)2​

Balanced equations for Q7:

1. PCl5​+H2​O→POCl3​+2HCl
2. 3Cu+8HNO3​→3Cu(NO3​)2​+4H2​O+2NO
3. (NH4​)2​Cr2​O7​→Cr2​O3​+N2​+4H2​O
4. 2KNO3​+H2​CO3​→K2​CO3​+2HNO3​