William W. answered • 11d

BS in Mechanical Engineering with 35 years experience

Time # 1:

m = 7.60 g

V = 27.0 L

Calculate the number of moles by dividing the mass *7.60 g) by the molar mass (15.999 x 2) = 31.998 g/mol to get 0.2375 moles

Time #2:

n = 0.2375 + 0.700 = 0.9375 moles

Using the ideal gas law:

PV = nRT with "R" being a constant.

So P/(RT) = n/V

For Time #1: P_{1}(RT_{1}) = n_{1}/V_{1}

And for Time #2: P_{2}(RT_{2}) = n_{2}/V_{2}

In both Time #1 and Time #2, P/(RT) are constants that remain the same therefore given that P_{1}(RT_{1}) = P_{2}(RT_{2}) then:

n_{1}/V_{1} = n_{2}/V_{2}

or V_{2} = n_{2}V_{1}/n_{1}

V_{2} = (0.9375)(27.0)/(0.2375)

V_{2} = 106.57 or, when rounded to the appropriate number of sig figs: V_{2} = 107 L