1) Answer is: double replacement.
Balanced chemical reaction: NaHCO₃ + HCl → NaCl + H₂CO₃.
Double replacement reactions (double displacement or metathesis reactions), two ionic compounds are exchanged, making two new compounds.
2) Answer is: decomposition.
Balanced chemical reaction: H₂CO₃ → H₂O + CO₂.
Decomposition is reaction where one substance is broken down into two or more simpler substances.