For a gas, which pair of variables are inversely proportional to each other (if all other conditions remain constant)?

Under conditions of fixed temperature and an amount of gas, Boyle's law requires that: 

 $I.\ P_1V_1\ =\ P_2V_2$  

 $II.\ \ P_1V_1\ =\ k$   

 $III.\ \ \ \frac{P_1}{V_2}=\frac{P_2}{V_1}$    

A sample of oxygen occupies 47.2 liters under a pressure of 1240 Pa at 25^oC. What volume would it occupy at 25^oC if the pressure were decreased to 730 Pa?

A sample of nitrogen occupies 5.50 liters under a pressure of 900 Pa at 25^oC. At what temperature will it occupy 10.0 liters at the same pressure?

A gas at 928 kpa, 129 ⁰C occupies a volume of 569 L. Calculate the volume at 319 kpa and 32 C.

If the pressure of a gas starts out at 200kPa and increases to 600kPa, what would the initial temperature be if it ended up at 300K?

When a cold tyre is inflated to a certain pressure and then is warmed up due to friction with the road, the pressure increases. This happens because the

Gas pressure is caused by

When you push down on a bike tyre, you feel resistance because

At 20^oC, the same volume of helium and hydrogen gas will have