Air was put into an automobile tire when the tire was cold, at 5.00 C. The tire's air pressure was 3.04 atm. Later, the weather warms up. Also, the automobile is driven, further warming the tire. What will the tire's pressure be when the temperature is 25.0 C?

Explanation:

Let suppose that air inside the tire behaves ideally. The equation of state for ideal gases is:

As tire can be modelled as a closed and rigid container, there are no changes in volume and number of moles. Hence, the following relationship is constructed:

The final pressure is:

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%