[tex]\Large\boxed{\begin{array}{l}\underline{\rm equac_{\!\!,}\tilde ao~balanceada:}\\\sf2H_2+O_2\longrightarrow 2H_2O\\\underline{\rm montagem~da~regra~de~tr\hat es:}\\\sf 36~g~de~H_2O\longrightarrow 22,4~L~de~O_2\\\sf x\longrightarrow 2~L~de~O_2\\\sf 22,4x=2\cdot36\\\sf x=\dfrac{72}{22,4}\\\sf x=3,21~g~de~H_2O\end{array}}[/tex]
