Which coefficient should appear in front of lino3 in the balanced equation?

Missing chemical reaction:
Pb(NO₃)₂(aq) + Li₂SO₄(aq) → PbSO₄(s) + LiNO₃(aq).
Answer is:
Balanced chemical reaction:
Pb(NO₃)₂(aq) + Li₂SO₄(aq) → PbSO₄(s) + 2LiNO₃(aq).
Number of atoms on both side of chemical reaction must be the same. There is two lithium atoms, two nitrogs, ten oxygen atoms, one lead and one sulfur on both side of balanced chemical reaction.

Idon't know hope someone you

Answer (b) supersaturation;