Malic acid (2-hydroxybutanedioic acid) có trong quả táo. Cho m gam malic acid tác dụng với Na dư, thu được \[{V_1}\] lít khí \[{H_2}\]. Mặt khác,

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Malic acid (2-hydroxybutanedioic acid) có trong quả táo. Cho m gam malic acid tác dụng với Na dư, thu được \[{V_1}\] lít khí \[{H_2}\]. Mặt khác, cho m gam malic acid tác dụng với \[NaHC{O_3}\] dư, thu được \[{V_2}\] lít khí \[C{O_2}\] (thể tích các khí được đo ở cùng điều kiện). Mối quan hệ giữa \[{V_1}\] và \[{V_2}\] là

\[2{V_1} = {\rm{ }}{V_2}\].

\[4{V_1} = {\rm{ }}3{V_2}.\]

\[{V_1} = {\rm{ }}{V_2}\].

\[2{V_1} = {\rm{ }}3{V_2}\].

Giải thích

Malic acid có công thức cấu tạo: \({\rm{HOOC}} - {\rm{CH}}({\rm{OH}}) - {\rm{C}}{{\rm{H}}_2} - {\rm{COOH}}\)

\(\begin{array}{l}{\rm{HOOC}} - {\rm{CH}}({\rm{OH}}) - {\rm{C}}{{\rm{H}}_2} - {\rm{COOH}} + 3{\rm{Na}} \to {\rm{NaOOC}} - {\rm{CH}}({\rm{ONa}}) - {\rm{C}}{{\rm{H}}_2} - {\rm{COONa}} + 1,5{{\rm{H}}_2}\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,a\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,1,5a\,\,mol\end{array}\)

\(\begin{array}{l}{\rm{HOOC}} - \mathop {\rm{C}}\limits_{|\,} {\rm{H}} - {\rm{C}}{{\rm{H}}_2} - {\rm{COOH}} + 2{\rm{NaHC}}{{\rm{O}}_3} \to {\rm{NaOOC}} - \mathop {\rm{C}}\limits_| {\rm{H}} - {\rm{C}}{{\rm{H}}_2} - {\rm{COONa}} + 2{\rm{C}}{{\rm{O}}_2} + 2{{\rm{H}}_2}{\rm{O}}\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,OH\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,OH\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{\rm{a}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{\rm{2a}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,{\rm{mol}}\end{array}\)

\( \Rightarrow \left\{ {\begin{array}{*{20}{l}}{{{\rm{n}}_{{{\rm{H}}_2}}} = 1,5{\rm{a}}}\\{{{\rm{n}}_{{\rm{C}}{{\rm{O}}_2}}} = 2{\rm{a}}}\end{array} \Rightarrow \frac{{{{\rm{V}}_1}}}{{\;{{\rm{V}}_2}}} = \frac{{1,5}}{2} \Rightarrow 4\;{{\rm{V}}_1} = 3\;{{\rm{V}}_2}} \right.\).

Chọn B.