Question

A neon-dioxygen mixture contains 70.6 g dioxygen and 167.5 g neon. if pressure of the mixture of gases in the cylinder is 25 bar, what is the partial pressure of dioxygen and neon in the mixture?

Answer 1

Answer: The partial pressure of dioxygen and neon in the mixture is 5.25 bar and 19.75 bar respectively.

Explanation:

To calculate the moles, we use the formula:

$Moles=\frac{\text{Given mass}}{\text{Molar mass}}$    

${\text {Moles of dioxygen}=\frac{70.6g}{32g/mol}=2.21moles$  

${\text {Moles of neon}=\frac{167.5g}{20g/mol}=8.38moles$

${\text {Total moles}=2.21moles+8.38moles=10.59moles$

${\text {Mole fraction of dioxygen}=\frac{\text {moles of dioxygen}}{\text {Total moles}}$    

${\text {Mole fraction of dioxygen}=\frac{2.21}{10.59}=0.21$    

${\text {Mole fraction of neon}=\frac{\text {moles of neon}}{\text {Total moles}}$    

${\text {Mole fraction of neon}=\frac{8.38}{10.59}=0.79$

${\text {partial pressure}={\text {mole fraction}}\times {\text {Total pressure}}$     

${\text {partial pressure of dioxygen}={0.21}\times {25bar}=5.25 bar$    ${\text {partial pressure of neon}={0.79}\times {25bar}=19.75bar$    

Answer 2

Answer:

The mass of dioxygen is 70.6 g.

The molar mass of dioxygen is 32 g/mol.

The number of moles of dioxygen

=  32 g/mol  

70.6 g  

​  

= 2.21 mol  

The mass of neon is 167.5 g.

The molar mass of neon is 20.2 g/mol.

The number of moles of neon

=   20.2 g/mol  

167.5 g  

​  

= 8.29 mol  

The total number of moles of neon and dioxygen = 2.21 + 8.29= 10.49  

The mole fraction of neon =  

10.49

8.29  

​  

= 0.789  

Total pressure in the cylinder is 25 bar.

The partial pressure of neon = 0.789 × 25 bar= 19.7 bar

The partial pressure of dioxygen = 25 bar − 19.7 bar = 5.3 bar