KCl +AgNO3 --> KNO3 + AgCl (1)
KBr +AgNO3 --> KNO3 +AgBr (2)
giả sử nKCl=x(mol)
nKBr=y(mol)
=>\(\left\{{}\begin{matrix}74,5x+119y=6,25\\143,5x+188y=10,39\end{matrix}\right.=>\left\{{}\begin{matrix}x=0,02\left(mol\right)\\y=0,04\left(mol\right)\end{matrix}\right.\)
=> nhh=0,06(mol)