a, V khí thoát ra(đktc)
b, CM dd thu được
___________________________________ a,
$n_{K_{2}SO_{3}}=0,3(mol)$
$K_{2}SO_{3}+HNO_{3}--->K_{2}SO_{4}+2NO_{2}+H_{2}O$
___0,3__0,3___________0,3___0,6__________
$V_{NO_{2}}=13,44(lít)$
b,
$V_{dd}$ sau=250+200=450(ml)=0,45(lít)
=>$C_{M}K_{2}SO_{4}$=$\frac{2}{3}$(M)