\(a.n_{CO_2}=\dfrac{0,00448}{22,4}=0,0002mol\\ Na_2CO_3+2HCl\rightarrow2NaCl+CO_2+H_2O\\ n_{HCl}=n_{NaCl}=0,0002.2=0,0004mol\\ C_{M_{HCl}}=\dfrac{0,0004}{0,04}=0,01M\\ b.n_{Na_2CO_3}=n_{CO_2}=0,0002mol\\ m_{NaCl}=0,0004.58,5+\left(10-0,0002.106\right)=10,022g\\ c,\%m_{Na_2CO_3}=\dfrac{0,0002.106}{10}\cdot100=0,212\%\\ \%m_{NaCl}=100-0,212=99,788\%\)