a) \(n_{CO_2}=\dfrac{7}{22,4}=\dfrac{5}{16}\left(mol\right)\)
\(n_{NaOH}=\dfrac{5,8}{40}=0,145\left(mol\right)\)
PTHH: 2NaOH + CO2 --> Na2CO3 + H2O
______0,145->0,0725-->0,0725
\(Na_2CO_3+CO_2+H_2O->2NaHCO_3\)
_0,0725->0,0725------------->0,145
=> Muối thu được là NaHCO3: 0,145 mol
b) CO2 dư
\(n_{CO_2\left(dư\right)}=\dfrac{5}{16}-0,145=0,1675\left(mol\right)\)