How to find how many grams of nitrogen would fill 240 L

Question

The problem says how many grams of nitrogen would fill a 240 L weather balloon to a pressure of 1.25 ATM at 29 degrees C

Answer 1

You want to use the Ideal gas Law for this problem since you have all the necessary information.

PV=nRT

Solve for n

PV/RT=n

plug in your information, remembering to use 0.08206 L·atm·mol−1·K−1 for R and to convert 29C to Kelvin.

Now you get how many moles of N you have.

12.09 moles N * 14.01g/mole N = 170 g. N

The key here is to see what information you have and to use the correct units. By always paying attention to the units, you can reduce most of your errors.

Answer 2

This question requires that you apply the Ideal Gas Law, which states:

PV=nRt

Where P is pressure  in atmospheres (1.25 atm)

V=volume in liters (240 L)

n=number of moles of gas (what we're looking for)

R= the ideal gas constant (.08206 L·atm·mol−1·K−1)

and T= temperature in kelvin (29 degrees C+273=302 K)

So:

(1.25)(240)=n(.08206)(302)

300=n(24.78)

n=300/24.78

n=12.11 moles

Then convert moles to grams:

12.11 mol*14.00g/mol=169.54 g N