\(b,n_{H_2SO_4}=\dfrac{4,9}{98}=0,05\left(mol\right)\\ C_{MddH_2SO_4}=\dfrac{0,05}{0,2}=0,25\left(M\right)\\ c,n_{HCl}=\dfrac{8,96}{22,4}=0,4\left(mol\right)\\ C_{MddHCl}=\dfrac{0,4}{0,25}=1,6\left(M\right)\\ d,C_{MddHCl}=\dfrac{C\%_{ddHCl}.10.d_{ddHCl}}{M_{HCl}}=\dfrac{7,3.10.1,25}{36,5}=2,5\left(M\right)\)