This is question 70 in the 2014 edition:
600 mL of a gas initially at 27 C and 755 torr will contain how many molecules?
Answer: 1.5 x 10^22 molecules
This answer was calculated using the ideal gas law. Even though these aren't standard conditions, should we use ideal gas law anyway if...
If the partial pressure of carbon dioxide is 30torr at STP, and nitrogen is the only other gas present, what is the percent by mass of carbon dioxide?
percent by mass = mass of CO2/total mass of gas
The book explains to find mole fraction...
So B is the correct answer, because deviation from ideal gas law is that that gas should have lower to none IMF, and no volume. I is wrong because it actually has greater volume, and III is wrong because KE doesn't event have an effect on ideal gases with the absence of T and velocity.