Đốt cháy hoàn toàn m gam chất béo X cần vừa đủ 54,096 lít O2, thu được 38,304 lít CO2 và x gam H2O

* Hướng dẫn giải

$\begin{array}{l}+XlàC_3{H}_5{\text{\hspace{0.17em}OOCR)}}_3\left(amol\right);n_{OtrongX}=6amol.\\ +Trongphản\text{\hspace{0.17em}\hspace{0.17em}ứ}ngthủyphân:n_{NaOH}=3n_X=3amol;n_{C_3{H}_5{\left(OH\right)}_3}=n_X=amol.\\ +\left\{\begin{array}{l}PƯcháy:\left\{\begin{array}{l}BTKL\Rightarrow m+32\underset{2,415}{\underbrace{n_{O_{{}_2}}}}=44\underset{1,71}{\underbrace{n_{C{O}_2}}}+18\underset{?}{\underbrace{n_{H_{2}O}}}\\ BTNT\Rightarrow 6a+2\underset{2,415}{\underbrace{n_{O_{{}_2}}}}=2\underset{1,71}{\underbrace{n_{C{O}_2}}}+\underset{?}{\underbrace{n_{H_{2}O}}}\end{array}\right.\\ PƯthủyphân:BTKL\Rightarrow m+3a.56=28,86+92a\end{array}\right.\Rightarrow \left\{\begin{array}{l}m=26,58\\ n_{H_{2}O}=1,59\\ a=0,03\end{array}\right.\Rightarrow \boxed{m_{H_{2}O}=28,62gam}\end{array}$

Chọn C