Đáp án & giải thích

\(14.C\)

\({\text{Phan ung xay ra khi tao ra ket tua}}{\text{, chat khi hoac chat dien ly yeu}}\)

\({\text{15}}{\text{.C}}\)

\({\text{H}}_3^{}PO_3^{}\;{\text{la chat dien ly trung binh}}{\text{, khong phai chat dien ly manh nen phan ung 2 chieu}}\)

\({\text{H}}_3^{}PO_4^{}\overset {} \leftrightarrows 3{H^ + } + PO_4^{3 - }\)

\(16.A\)

\(17.B\)

\(pH{\text{ cang tang thi do axit cang giam va tinh bazo cang tang}}\)

\({\text{18}}{\text{.A}}\)

\({\text{Cac ion trong cung` 1 dung dich tao ra ket tua}}{\text{, khi}}{\text{, chat dien ly yeu khong the o cung 1 dung dich}}\)

\({\text{19}}{\text{.B}}\)

\({\text{Phan ung xay ra khi tao ra ket tua}}{\text{, chat khi hoac chat dien ly yeu}}\)

\(20.({H^ + }).{\text{(}}O{H^ - }{\text{)}} = {10^{ - 14}}\)

\({\text{(}}{H^ + }{\text{)}} = \frac{{{{10}^{ - 14}}}}{{{{2.10}^{ - 3}}}} = {5.10^{ - 12}} < {10^{ - 7}}\)

\( \to D\)