Câu 2:$n_{H^+}=0,02.0,5=0,01 mol$ $n_{OH^-}=0,018.0,5=0,009 mol$$\Rightarrow n_{H^+_{dư}}=0,001 mol\Rightarrow [H^+_{dư}]=\frac{0,001}{0,5+0,5}=0,001\Rightarrow pH=-\lg(0,001)= 3$
Câu 2:$n_{H^+}=0,02.0,5=0,01 mol$ $n_{OH^-}=0,018.0,5=0,009 mol$$\Rightarrow n_{H^+_{dư}}=0,001 mol\Rightarrow [H^+_{dư}]=\frac{0,001}{0,5}=0,002\Rightarrow pH=-\lg(0,002)\approx 2,7$
Câu 2:$n_{H^+}=0,02.0,5=0,01 mol$ $n_{OH^-}=0,018.0,5=0,009 mol$$\Rightarrow n_{H^+_{dư}}=0,001 mol\Rightarrow [H^+_{dư}]=\frac{0,001}{0,5
+0,5}=0,00
1\Rightarrow pH=-\lg(0,00
1)
= 3$