[RobertT]

6.00g of helium gas was blown into a fairground balloon. On the day, the temperature was 28 degrees Celsius and the pressure inside the balloon was 103.4 kPa. Assuming it is infinitely elastic, to what volume did the balloon inflate.

Firstly i did n(he) = m/M = 6/8(Because it is He₂) which came out to be 0.75mol
I then proceeded to transpose the formula into V=nRT/p = 0.75 x 8.314 x 301 / 103.4
The final answer i got was 18.15L but the answer in the book says it is 36.3 L

I'm not sure if i calculated the Mol incorrectly or not.
Appreciate any help.
Cheers, Rob

[billnotgatez]

Because it is He2

Are you sure?

[RobertT]

Because it is He2

Are you sure?

Ahhh, i know where i went wrong now, I forgot that He was initially a gas and i thought it would be set up like N₂ gas. Thanks for the clear up, found out where i went wrong. Thanks again.

[billnotgatez]

Why is He not like N₂?
This is a basic concept you should understand

[RobertT]

I was thinking of placing the Helium in the same form as Nitrogen Gas, as in N₂, i wasn't thinking so i put the whole Helium formula down as He₂ instead of He. This made the Molar mass 8 instead of 4 changing the mol from 0.75 to 1.5. This is what i meant.
Thanks again for helping me out, I'll keep that concept in mind.
Cheers, Rob.

[billnotgatez]

I am sorry that I was not making my point clear

What is there about He Ne Ar that is different than H₂ O₂ N₂

[RobertT]

I am sorry that I was not making my point clear

What is there about He Ne Ar that is different than H₂ O₂ N₂

Ahh, He, Ne and Ar are all noble gasses, meaning the outershell is full, therefore it is extremely difficult to make them react unlike oxygen, nitrogen, etc.

I'm guessing what you're getting at is, He is just He on it's own as a gas, because it doesn't need to react with any other substance.

I totally forgot about this. Hehe guess i need to go back to the basics if I want to be fully prepared for Unit 3/4 Chem.
I've said this a lot, but thanks again for the help. Really appreciate it

[billnotgatez]

most excellent