How many grams of Kr are in a 7.40 L cylinder at 31.9 ∘C and 5.05 atm?

Question

How many grams of Kr are in a 7.40 L cylinder at 31.9 ∘C and 5.05 atm?

Answer 1

Hi Emily! We need to use the equation PV = nRT to solve for the moles of Kr in the cylinder, which will let us solve for the grams. We can rearrange the equation so that:

n = PV/RT ------> n = (5.05 atm)(7.4 L)/(0.0821 Lxatm/molxK)(304.9 K) ----> n = 1.5 moles

Then, using the molar mass of Kr, 84 g/mol, we can solve for the number of grams:

1.5 moles x 84 g/mol = 126 g Kr!

Hope this helps! Let me know if you need any other help!!