I tried this problem a lot of times, but just didnt get the answer.(adsbygoogle = window.adsbygoogle || []).push({});

The molecular mass of helium is 4 g/mol,

the Boltzmann’s constant is 1.38066 × 10−23 J/K, the universal gas constant is

8.31451 J/K · mol, and Avogadro’s number

is 6.02214 × 1023 1/mol. Given: 1 atm =

101300 Pa.

How many atoms of helium gas are required

to fill a balloon to diameter 24 cm at 76◦C and

0.789 atm?

What I did was find the volume and then use pv = nrt to find the moles. From the moles I found number of atoms. But it was wrong. Help Please.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Gases and avogadros number

**Physics Forums | Science Articles, Homework Help, Discussion**