Copper sulphate

How much g of water do we have to add to 240 g of an 84% CuSO4 solution to produce a 60% solution? (Express the mass of crystalline CuSO4 in the original solution and the resulting solution and compare them. )

Final Answer:

w =  96 g
m₁ =  201.6 g
m₂ =  201.6 g

Step-by-step explanation:

$$\begin{gathered} c_1=84\%=\frac{84}{100}=\frac{21}{25}=0.84 \\ {c}_2=60\%=\frac{60}{100}=\frac{3}{5}=0.6 \\ m=240\text{g} \\ {c}_1\cdot m=c_2\cdot (m+w) \\ 0.84\cdot 240=0.6\cdot (240+w) \\ 0.6w=57.6 \\ w=\frac{57.6}{0.6}=96 \\ w=96=96\text{g} \end{gathered}$$

$m_1=c_1\cdot m=0.84\cdot 240=201.6\text{g}$

$$\begin{gathered} m_2=c_2\cdot (m+w)=0.6\cdot (240+96)=\frac{1008}{5}=201.6 \\ {m}_2=m_1=201.6\text{g} \end{gathered}$$

Try another example