Đáp án:
9,26g
Giải thích các bước giải:
\(\begin{array}{l}
nCuS{O_4}.5{H_2}O = \dfrac{x}{{250}}\,mol\\
\Rightarrow nCuS{O_4} = nCuS{O_4}.5{H_2}O = \dfrac{x}{{250}}\,mol\\
nCuS{O_4}\,trong\,{\rm{dd}}\,{\rm{5\% }} = \frac{{100 \times 5\% }}{{160}} = 0,03125\,mol\\
nCuS{O_{4\,}}\,trongA = \dfrac{x}{{250}} + 0,03125\,mol\\
m{\rm{dd}}A = 100 + x(g)\\
\dfrac{{(\dfrac{x}{{250}} + 0,03125) \times 160}}{{100 + x}} = 10\% \Rightarrow x = 9,26g
\end{array}\)