Gases Quiz

The empirical formula for this gas can be found to be C₂H₅. The molar mass can be found to be 58g, giving the overall molecular formula as C₄H₁₀.

As per the vapor pressure theory, when the quantity of liquid in a closed container is doubled at constant temperature, the vapor pressure of the liquid will also get doubled. This is because the vapor pressure of a liquid is directly proportional to the number of molecules present in the gaseous state above the liquid surface.

The behaviour of a real gas will best approximate the behaviour of an ideal gas when the gas particles have negligible volume and do not interact with each other, and when the temperature is high and pressure is low.

P₁/T₁ = P₂/T₂. Do not forget to change the units of temperature to Kelvin.

P₁V₁ = P₂V₂

First change the mass in grams, then use PV=nRT ensuring that the units are m³ and Kelvin. The answer obtained will be in Pa.

1 mole of any gas occupies the same volume, therefore all number of moles will be equal.

The mole fraction is equivalent to the pressure of substance over total pressure.

1. Gas molecules are small and have negligible volume compared to the volume of the container they are in.

2. Gas molecules are in constant random motion, colliding with each other and the walls of the container.

3. All collisions between gas molecules and between gas molecules and the walls of the container are elastic, meaning that no energy is lost during the collision.

4. The total kinetic energy of the gas molecules is directly proportional to the temperature of the gas in Kelvin.

5. Gas molecules do not interact with each other except during collisions.

6. The average kinetic energy of gas molecules is proportional to the temperature of the gas.

7. The pressure of a gas is caused by the molecules colliding with the walls of the container and is proportional to the number of collisions per unit area.

Speed is related to the mass making CCl₄ the slowest as it the highest molar mass whilst He would be the fastest as it is the lightest.