752 mmHg 21.0℃ 1.566 g Zn excess HCl 18.65 mmHg

752 mmHg 21.0℃ 1.566 g Zn excess HCl 18.65 mmHg

 

 

In the laboratory, hydrogen gas is usually made by the following reaction:

Zn(s) + 2HCl(aq) → H2(g) + ZnCl2(aq)

How many liters of H2 gas, collected over water

at an atmospheric pressure of 752 mmHg and a temperature of 21.0℃,

can be made from 1.566 g of Zn and excess HCl?

The partial pressure of water vapor is 18.65 mmHg at 21.0℃.

 

---------------------------------------------------

 

Zn의 몰질량 = 65.38 g/mol 이므로,

1.566 g / (65.38 g/mol) = 0.02395 mol Zn

( 참고 https://ywpop.tistory.com/7738 )

 

 

 

Zn(s) + 2HCl(aq) → H2(g) + ZnCl2(aq)

Zn : H2 = 1 : 1 계수비(= 몰수비) 이므로,

0.02395 mol Zn 반응시,

생성되는 H2의 몰수 = 0.02395 mol

 

 

 

752 – 18.65 = 733.35 mmHg

---> H2 기체의 압력

( 참고 https://ywpop.tistory.com/3490 )

 

 

 

PV = nRT 로부터,

( 참고 https://ywpop.tistory.com/3097 )

 

H2 기체의 부피를 계산하면,

V = nRT / P

= (0.02395) (0.08206) (273.15+21.0) / (733.35/760)

= 0.599 L

 

 

 

답: 0.599 L

 

 

 

 

[키워드] 수상포집 기준문서, 수상치환 기준문서