Question

dẫn từ từ V lít khí H2 đi qua 24 g bột Fe2O3 nung nóng, sau 1 thời gian thu được 19,2 g chất rắn A. để khử hết A cần dùng tối thiểu bao nhiêu cm3 khí H2

Answer 1

\(n_{Fe_2O_3}=\dfrac{m}{M}=\dfrac{24}{160}=0,15\left(mol\right)\\ n_{Fe}=\dfrac{m}{M}=\dfrac{19,2}{56}=\dfrac{12}{35}\left(mol\right)\)

\(pthh:\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }Fe_2O_3+3H_2\overset{t^0}{\rightarrow}2Fe+3H_2O\)

\(Theo\text{ }pthh:1mol\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }3mol\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }2mol\)

\(Theo\text{ }đb:0,15mol\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\dfrac{12}{35}mol\)

Phản ứng:\(\dfrac{0,15mol}{ }\text{ }\text{ }0,45mol\text{ }\text{ }\text{ }\dfrac{0,3mol}{ }\)

\(\text{Sau pứ: }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }0\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\dfrac{3}{70}mol\)

\(\Rightarrow V_{H_2}=n\cdot22,4=0,45\cdot22,4=10,08\left(l\right)=1008\left(cm^3\right)\)