a)
\(C_{M_{NaOH}}=\dfrac{0.5}{0.25}=2\left(M\right)\)
b)
\(C\%_{CuSO_4}=\dfrac{50}{200}\cdot100\%=25\%\)
c)
\(m_{dd_{KCl}}=20+580=600\left(g\right)\)
\(C\%_{KCl}=\dfrac{20}{600}\cdot100\%=3.33\%\)
d)
\(C_{M_{CuSO_4}}=\dfrac{1.5}{0.75}=2\left(M\right)\)