Question

Hòa tan 12.4 g NaOH vào 37.6 ml H2O. tính C% dd tạo thành

 

Answer 1

\(m_{H_2O}=37,6.1=37,6\left(g\right)\\ m_{ddNaOH}=12,4+37,6=50\left(g\right)\\ C\%_{ddNaOH}=\dfrac{12,4}{50}.100=24,8\%\)

Answer 2

Ta có: \(D_{H_2O}=1\left(g/mol\right)\Rightarrow m_{H_2O}=37,6.1=37,6\left(g\right)\)

\(\Rightarrow C\%_{ddNaOH}=\dfrac{12,4.100\%}{37,6}=32,98\%\)