`[H^+]=[0,02.0,2+0,05.2.0,2]/[0,2+0,2]=0,06(M)`
`=>pH=-log(0,06)=1,22`
____________________________________________________
`H^[+] + OH^[-] -> H_2 O`
`0,1` `0,1` `(mol)`
`n_[H^+]=1.0,1=0,1(mol)`
`n_[OH^-]=0,375.0,4=0,15(mol)`
`=>[OH^-]=[0,15-0,1]/[0,1+0,4]=0,1(M)`
`=>[H^+]=[10^[-14]]/[0,1]=10^[-13](M)`
`=>pH=13`