a) Sửa đề: dd HCl 0,1 M
\(pH=-log\left[H^+\right]=-log\left[0,1\right]=1\)
b) Ta có: \(\left[H^+\right]=0,025\cdot2=0,05\left(M\right)\)
\(\Rightarrow pH=-log\left[H^+\right]\approx1,3\)
c) Ta có: \(pH=14+log\left[OH^-\right]=14+log\left(0,1\right)=13\)
d) \(pH=14+log\left[OH^-\right]=14+log\left(0,04\cdot2\right)\approx12,9\)