Question

Jeff and Jill go canoeing. While reaching to feed a duck, the boat flips. Jeff and Jill blow up their inflatable life preservers and then put them on. As they wait for the rescue squad, they calculate how much nitrogen is in each life preserver. They estimate that the volume is 14 L, pressurized to 1.1 atm at 25°C. The air used for inflation is 80% nitrogen by volume and 20% oxygen by volume. Give the amount of nitrogen gas. Answer in units of grams.

Answer 1

Answer:

14 g

Explanation:

First, we have to calculate the partial pressure of N₂. We know that the air is 80% nitrogen by volume, which, for a gas mixture, means that the mole fraction of N₂ is 0.80.

We can calculate the partial pressure of N₂ (pN₂) using the following expression:

pN₂ = P . x(N₂)

where,

P is the total pressure

x(N₂) is the mole fraction of N₂

pN₂ = 1.1 atm . 0.80 = 0.88 atm

Then, we can calculate the moles of N₂ using the ideal gas equation.

$P.V=n.R.T\\n=\frac{P.V}{R.T} =\frac{0.88atm.14L}{(0.082atm.L/mol.K).(25 +273)K} =0.50mol$

Considering that the molar mass of N₂ is 28.01 g/mol, the mass of N₂ is:

$0.50mol.\frac{28.01g}{mol} =14g$