Đặt CuSO4.5H2O là a mol
\(\rightarrow\text{nH2O=5a}\rightarrow\text{mH2O=90a g}\rightarrow\text{V H2O=90a ml}\)
400g CuSO4 0,2%\(\rightarrow\)nCuSO4=0,005
\(\rightarrow\text{nCuSO4=a+0,005}\)
\(V_{dd}=\frac{400}{1,1}=\frac{4000}{11}ml\)
\(\rightarrow\)V dd sau khi cho tinh thể là \(\frac{\text{90a+4000}}{11ml}\)
Ta có :
\(\frac{\text{a+0.005}}{\frac{\text{90a+4000}}{\frac{\text{11}}{\text{1000}}}}=1\)
\(\rightarrow\text{a=0.4}\rightarrow\text{mtinh thể=0,4.250=100}\)
https://i.imgur.com/7oikWVn.jpg
