Question

cho 50g CuSO4.5H₂O cho vào m (g) dd CuSO₄ 16% tạo thành dd CuSO₄ 48%. tính m

Answer 1

\(n_{CuSO_4.5H_2O}=\frac{50}{250}=0,2\left(mol\right)\)

Ta có: \(n_{CuSO_4}\left(trongtt\right)=n_{CuSO_4.5H_2O}=0,2\left(mol\right)\)

\(\Rightarrow m_{CuSO_4}\left(trongtt\right)=0,2\times160=32\left(g\right)\)

\(m_{CuSO_4.16\%}=16\%m=0,16m\left(g\right)\)

Ta có: \(m_{CuSO_4.48\%}=m_{CuSO_4}\left(trongtt\right)+m_{CuSO_4.16\%}=32+0,16m\left(g\right)\)

Ta có: \(m_{ddCuSO_4.48\%}=50+m\left(g\right)\)

\(C\%_{CuSO_4.48\%}=\frac{32+0,16m}{50+m}\times100\%=48\%\)

\(\Leftrightarrow\frac{32+0,16m}{50+m}=0,48\)

\(\Rightarrow32+0,16m=24+0,48m\)

\(\Leftrightarrow8=0,32m\)

\(\Leftrightarrow m=25\left(g\right)\)