\(m_{dd_{CuSO_4}}=a\left(g\right)\)
\(\Rightarrow m_{CuSO_4}=0.08a\left(g\right)\)
\(m_{CuSO_4\cdot5H_2O}=b\left(g\right)\)
\(\Rightarrow m_{CuSO_4}=\dfrac{b}{250}\cdot160=0.64b\left(g\right)\)
\(m_{dd_{CuSO_4\left(15\%\right)}}=a+b=560\left(g\right)\left(1\right)\)
\(m_{CuSO_4\left(15\%\right)}=0.08a+0.64b=560\cdot16\%=89.6\left(g\right)\left(2\right)\)
\(\left(1\right),\left(2\right):a=480,b=80\)
Gọi $m_{dd\ CuSO_4\ 8\%} = a(gam) ; n_{CuSO_4.5H_2O} = b(mol)$
Sau khi pha :
$m_{CuSO_4} = a.8\% + 160a = 560.16\% = 89,6(gam)$
$m_{dung\ dịch} = a + 250b = 560(gam)$
Suy ra a = 480(gam) ; b = 0,32(mol)$
$m_{CuSO_4.5H_2O} = 0,32.250 = 80(gam)$