5. A flask containing 90.0 mL of hydrogen gas was collected under a pressure of 97.5 atm. At what pressure, at atm, would the volume be 070 L?

0.125 atm

Explanation:

From the question,

Applying boyles law

PV = P'V' Equation 1

Where P = Initial pressure, V = Initial volume, P' = Final pressure, V' = final Volume.

make P' the subject of the equation

P' = PV/V' Equation 2

Given: P = 97.5 atm, V = 90 mL = 0.09 L, V' = 70 L.

Substitute these values into equation 2

P' = 97.5×0.09/70

P' = 0.125 atm

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%