Hỗn hợp <span class="MathJax_Preview" style="color: inherit; display: none;"></span><span id="MathJax-Element-1-Frame" class="mjx-chtml MathJax_CHTML" tabindex="0" data-mathml="<math xmlns="http://www.w3.org/1998/Math/MathML"><mrow class="MJX-TeXAtom-ORD"><mi>X</mi></mrow></math>" role="presentation" style="font-size: 127%; position: relative;"><span id="MJXc-Node-1" class="mjx-math" aria-hidden="true"><span id="MJXc-Node-2" class="mjx-mrow"><span id="MJXc-Node-3" class="mjx-texatom"><span id="MJXc-Node-4" class="mjx-mrow"><span id="MJXc-Node-5" class="mjx-mi"><span class="mjx-char MJXc-TeX-math-I" style="padding-top: 0.445em; padding-bottom: 0.298em; padding-right: 0.024em;">X</span></span></span></span></span></span><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"><mrow class="MJX-TeXAtom-ORD"><mi>X</mi></mrow></math></span></span><script type="math/tex" id="MathJax-Element-1"> {X}</script> gồm <span class="MathJax_Preview" style="color: inherit; display: none;"></span><span id="MathJax-Element-2-Frame" class="mjx-chtml MathJax_CHTML" tabindex="0" data-mathml="<math xmlns="http://www.w3.org/1998/Math/MathML"><mstyle mathsize="1.44em"><msub><mrow class="MJX-TeXAtom-ORD"><mi>C</mi></mrow><mrow class="MJX-TeXAtom-ORD"><mn>2</mn></mrow></msub><msub><mrow class="MJX-TeXAtom-ORD"><mi>H</mi></mrow><mrow class="MJX-TeXAtom-ORD"><mn>5</mn></mrow></msub><mrow class="MJX-TeXAtom-ORD"><mi>O</mi><mi>H</mi></mrow><mo>,</mo></mstyle></math>" role="presentation" style="font-size: 127%; position: relative;"><span id="MJXc-Node-6" class="mjx-math" aria-hidden="true"><span id="MJXc-Node-7" class="mjx-mrow"><span id="MJXc-Node-8" class="mjx-mstyle"><span id="MJXc-Node-9" class="mjx-mrow" style="font-size: 144%;"><span id="MJXc-Node-10" class="mjx-msubsup"><span class="mjx-base" style="margin-right: -0.045em;"><span id="MJXc-Node-11" class="mjx-texatom"><span id="MJXc-Node-12" class="mjx-mrow"><span id="MJXc-Node-13" class="mjx-mi"><span class="mjx-char MJXc-TeX-math-I" style="padding-top: 0.495em; padding-bottom: 0.298em; padding-right: 0.045em;">C</span></span></span></span></span><span class="mjx-sub" style="font-size: 70.7%; vertical-align: -0.212em; padding-right: 0.071em;"><span id="MJXc-Node-14" class="mjx-texatom" style=""><span id="MJXc-Node-15" class="mjx-mrow"><span id="MJXc-Node-16" class="mjx-mn"><span class="mjx-char MJXc-TeX-main-R" style="padding-top: 0.396em; padding-bottom: 0.347em;">2</span></span></span></span></span></span><span id="MJXc-Node-17" class="mjx-msubsup"><span class="mjx-base" style="margin-right: -0.057em;"><span id="MJXc-Node-18" class="mjx-texatom"><span id="MJXc-Node-19" class="mjx-mrow"><span id="MJXc-Node-20" class="mjx-mi"><span class="mjx-char MJXc-TeX-math-I" style="padding-top: 0.445em; padding-bottom: 0.298em; padding-right: 0.057em;">H</span></span></span></span></span><span class="mjx-sub" style="font-size: 70.7%; vertical-align: -0.212em; padding-right: 0.071em;"><span id="MJXc-Node-21" class="mjx-texatom" style=""><span id="MJXc-Node-22" class="mjx-mrow"><span id="MJXc-Node-23" class="mjx-mn"><span class="mjx-char MJXc-TeX-main-R" style="padding-top: 0.396em; padding-bottom: 0.347em;">5</span></span></span></span></span></span><span id="MJXc-Node-24" class="mjx-texatom"><span id="MJXc-Node-25" class="mjx-mrow"><span id="MJXc-Node-26" class="mjx-mi"><span class="mjx-char MJXc-TeX-math-I" style="padding-top: 0.495em; padding-bottom: 0.298em;">O</span></span><span id="MJXc-Node-27" class="mjx-mi"><span class="mjx-char MJXc-TeX-math-I" style="padding-top: 0.445em; padding-bottom: 0.298em; padding-right: 0.057em;">H</span></span></span></span><span id="MJXc-Node-28" class="mjx-mo"><span class="mjx-char MJXc-TeX-main-R" style="margin-top: -0.145em; padding-bottom: 0.544em;">,</span></span></span></span></span></span><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"><mstyle mathsize="1.44em"><msub><mrow class="MJX-TeXAtom-ORD"><mi>C</mi></mrow><mrow class="MJX-TeXAtom-ORD"><mn>2</mn></mrow></msub><msub><mrow class="MJX-TeXAtom-ORD"><mi>H</mi></mrow><mrow class="MJX-TeXAtom-ORD"><mn>5</mn></mrow></msub><mrow class="MJX-TeXAtom-ORD"><mi>O</mi><mi>H</mi></mrow><mo>,</mo></mstyle></math></span></span><script type="math/tex" id="MathJax-Element-2">\Large{C}_{2} {H}_{5} {OH},</script> <span class="MathJax_Preview" style="color: inherit; display: none;"></span><span id="MathJax-Element-3-Frame" class="mjx-chtml MathJax_CHTML" tabindex="0" data-mathml="<math xmlns="http://www.w3.org/1998/Math/MathML"><mstyle mathsize="1.44em"><mrow class="MJX-TeXAtom-ORD"><mi>H</mi><mi>C</mi><mi>H</mi><mi>O</mi></mrow><mo>,</mo></mstyle></math>" role="presentation" style="font-size: 127%; position: relative;"><span id="MJXc-Node-29" class="mjx-math" aria-hidden="true"><span id="MJXc-Node-30" class="mjx-mrow"><span id="MJXc-Node-31" class="mjx-mstyle"><span id="MJXc-Node-32" class="mjx-mrow" style="font-size: 144%;"><span id="MJXc-Node-33" class="mjx-texatom"><span id="MJXc-Node-34" class="mjx-mrow"><span id="MJXc-Node-35" class="mjx-mi"><span class="mjx-char MJXc-TeX-math-I" style="padding-top: 0.445em; padding-bottom: 0.298em; padding-right: 0.057em;">H</span></span><span id="MJXc-Node-36" class="mjx-mi"><span class="mjx-char MJXc-TeX-math-I" style="padding-top: 0.495em; padding-bottom: 0.298em; padding-right: 0.045em;">C</span></span><span id="MJXc-Node-37" class="mjx-mi"><span class="mjx-char MJXc-TeX-math-I" style="padding-top: 0.445em; padding-bottom: 0.298em; padding-right: 0.057em;">H</span></span><span id="MJXc-Node-38" class="mjx-mi"><span class="mjx-char MJXc-TeX-math-I" style="padding-top: 0.495em; padding-bottom: 0.298em;">O</span></span></span></span><span id="MJXc-Node-39" class="mjx-mo"><span class="mjx-char MJXc-TeX-main-R" style="margin-top: -0.145em; padding-bottom: 0.544em;">,</span></span></span></span></span></span><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"><mstyle mathsize="1.44em"><mrow class="MJX-TeXAtom-ORD"><mi>H</mi><mi>C</mi><mi>H</mi><mi>O</mi></mrow><mo>,</mo></mstyle></math></span></span><script type="math/tex" id="MathJax-Element-3">\Large{HCHO},</script> $\Lar

Hỗn hợp X gồm C2H5OH, HCHO, $\Lar

4/5

Tác giả: Thầy Tùng

Đăng ngày: 18 Aug 2022

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Câu hỏi:

Hỗn hợp X gồm C2H5OH, HCHO, CH3COOH, HCOOCH3, CH3COOC2H3, CH2OHCH(OH)CHOCH3CH(OH)COOH. Đốt cháy hoàn toàn 13,8 gam X cần dùng vừa đủ 12,04 lít O2 (đktc) thu được CO2 và 9 gam H2O. Thành phần phần trăm theo khối lượng của CH3COOC2H3 trong X gần nhất với giá trị là

Đáp án án đúng là: B

Lời giải chi tiết:

Hỗn hợp X gồm C2H6O,CH2O,C2H4O2,C4O6O2,C3H6O3

Nhận thấy C3H6O3=CH2O+C2H4O2

Coi hỗn hợp X gồm C2H6O: a (mol), CH2O: b (mol), C2H4O2: c (mol), C4O6O2: d (mol)

BTKL: mCO2=13,8+0,5375.329=22 g

nCO2=0,5 mol

nH2O=nCO2=0,5 mol

a=d (1)

nCO2=2a+b+2c+4d=0,5 (2) 

BTNT O: a+b+2c+2d=0,5.2+0,50,5375.2=0,425 (3)

Lấy (2) - (3): a+2d=0,075 (4)

Giải hệ (1) và (4): a=d=0,025 

%C4H6O2=0,025.8613,8100%=15,58%