Question

A mixture of hydrogen and oxygen gases, in a 9.90 L Mask at 66°C, contains 0.586 grams of hydrogen and 4.94 grams of oxygen. The partial pressure of oxygen in the flask is atm and the total pressure in the flask is atm. som man viena no en una menos un Retry Entire Group 1 more group attempt remaining

Answer 1

1)

Molar mass of O2 = 32 g/mol

mass(O2)= 4.94 g

use:

number of mol of O2,

n = mass of O2/molar mass of O2

=(4.94 g)/(32 g/mol)

= 0.1544 mol

Given:

V = 9.9 L

n = 0.1544 mol

T = 66.0 oC

= (66.0+273) K

= 339 K

use:

P * V = n*R*T

P * 9.9 L = 0.1544 mol* 0.08206 atm.L/mol.K * 339 K

P = 0.4339 atm

Answer: 0.434 atm

2)

1st find the partial pressure of H2

Molar mass of H2 = 2.016 g/mol

mass(H2)= 0.586 g

use:

number of mol of H2,

n = mass of H2/molar mass of H2

=(0.586 g)/(2.016 g/mol)

= 0.2907 mol

Given:

V = 9.9 L

n = 0.2907 mol

T = 66.0 oC

= (66.0+273) K

= 339 K

use:

P * V = n*R*T

P * 9.9 L = 0.2907 mol* 0.08206 atm.L/mol.K * 339 K

P = 0.817 atm

Now use:

Total pressure = p(O2) + p(He)

= 0.434 atm + 0.817 atm

= 1.25 atm

Answer: 1.25 atm