Answer :
a) HNO₈ + Ca(NO₃)₂ ⇒ Ca(NO₃)₂+ H₂O this equation is wrong. Its impossible to balance.
Products are missing.
b) 2NaOH + H₂SO₄ ⇒ Na₂SO₄ + 2H₂O
Products are missing.
b) 2NaOH + H₂SO₄ ⇒ Na₂SO₄ + 2H₂O