Answer:
70.8 mmHg
Explanation:
To find partial pressure of carbon dioxide we first find the mole fraction of carbon dioxide
n (carbon dioxide) = 5/44.01 g/mol = 0.11361 mol
n (Helium) = 3.75 g/4 g/mol = 0.9375 mol
The partial pressure of carbon dioxide will be the mole fraction of carbon dioxide multiplied by the total pressure
Partial pressure = 0.11361g/(0.11361g + 0.9375 g)* 655 mmHg
= 70.8 mmHg