Ta có :
\(\text{nBaCl2=512x20%/208=32/65(mol)}\)
nBaCl2 dư=nH2SO4=100x9,8%/98=0,1(mol)
=>nBaCl2 phản ứng=32/65-0,1=51/130(mol)
Gọi a là m dd A
\(\text{mx17,4%/174+mx14,2%/142=51/130}\)
=>m=196,15(g)
b)m dd spu=196,15+512-51/130x233=616,74(g)
\(\text{C%KCl=2x0,19615x74,5/616,74=4,74%}\)
\(\text{C%NaCl=2x0,19615x58,5/616,74=3,72% }\)