https://i.imgur.com/3BK2ZOl.jpg
Bài đầy đủ nhé :
a)
nBa(OH)2=\(\frac{\text{ 200.17,1%}}{171}\) 0,2 mol
nH2SO4= \(\frac{\text{100.29,4%}}{98}\)=0,3 mol
Ba(OH)2 + H2SO4→ BaSO4↓ + 2H2O
0,2_____0,2______ 0,2
mBaSO4= 0,2.233=46,6 g
b)
C%H2SO4 dư=\(\frac{0,1.98}{20+100-46,6}\text{.100%= 3,87% }\)