744 mmHg 20℃ O2 gas 456 mL O2 gas mass

744 mmHg 20℃ O2 gas 456 mL O2 gas mass

 

 

744 mmHg, 20.℃에서 수상 포집으로 O2 gas 456 mL를 얻었다.

건조된 O2 gas의 질량(g)을 구하시오.

 

 

A 456 mL sample of oxygen gas was collected over water

at a pressure of 744 mmHg and a temperature of 20.℃.

 

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> 20℃ 수증기압 = 17.5 mmHg

( 참고 https://ywpop.tistory.com/5014 )

 

 

 

P_tot = P_O2 + P_H2O

 

P_O2 = P_tot – P_H2O

= 744 – 17.5

= 726.5 mmHg

 

 

 

PV = nRT

( 참고 https://ywpop.tistory.com/3097 )

 

n = PV / RT

= [(726.5/760) (0.456)] / [(0.08206) (273.15+20)]

= 0.0181 mol O2

 

 

 

O2의 몰질량 = 32 g/mol 이므로,

0.0181 mol × (32 g/mol) = 0.579 g O2