Question

Determine a massa molecular de um gás, sabendo-se que 0,500 g desse gás ocupa o volume de 1,12 L a 273 °C e 2,00 atm. Qual valor se encontra para a massa molecular desse gás?(Dado: R = 0,082 atm.L/mol.K) *
8 pontos
a) 10g/mol
b) 16g/mol
c) 20g/mol
d) 12g/mol​

Answer 1

$\large\boxed{\begin{array}{l}\underline{\rm Equac_{\!\!,}\tilde ao~de~Clapeyron}\\\sf P\cdot V=n\cdot R\cdot T\\\begin{cases}\sf P\longrightarrow press\tilde ao~medida~em~atm\\\sf V\longrightarrow volume~em~Litros\\\sf n\longrightarrow n\acute umero~de~mols\\\sf R\longrightarrow constante~universal~dos~gases\\\sf T\longrightarrow temperatura~em~Kelvin\end{cases}\\\underline{\rm Convers\tilde ao~de~Celsius~para~Kelvin}\\\sf t_K=t_C+273\end{array}}$

$\large\boxed{\begin{array}{l}\tt dados\begin{cases}\sf m=0,500g\\\sf V=1,12~L\\\sf T_C=273\implies T_K=273+273=546~\\\sf P=2~atm\\\sf n=?\end{cases}\\\sf P\cdot V=n\cdot R\cdot T\\\sf 2\cdot1,12=n\cdot 0,082\cdot546\\\sf n=\dfrac{2,24}{44,772}\\\sf n=0,05~mols\\\sf n=\dfrac{m}{mm}\\\sf 0,05=\dfrac{0,5}{mm}\\\\\sf mm=\dfrac{0,5}{0,05}\\\\\sf mm=10~g/mol\\\huge\boxed{\boxed{\boxed{\boxed{\sf\maltese~alternativa~a}}}}\end{array}}$