Calculating Net Charge of a Gas with Lost Electrons

[just.karl]

A container holds a gas consisting of 1.75 moles of oxygen molecules. One in a million of these molecules has lost a single electron. What is the net charge of the gas.


1.6 x 10^-19(C/e^-) x n(e^-)

So I'm looking for the number of electrons (n) which I think is 1.05625 x 10^19 and the final answer would be .169C. "Working backwards from the answer in the back" but I do not understand how I would figure out the number of electrons. Help?

 

[alphysicist]

Hi just.karl,

A container holds a gas consisting of 1.75 moles of oxygen molecules. One in a million of these molecules has lost a single electron. What is the net charge of the gas.


1.6 x 10^-19(C/e^-) x n(e^-)

So I'm looking for the number of electrons (n) which I think is 1.05625 x 10^19 and the final answer would be .169C. "Working backwards from the answer in the back" but I do not understand how I would figure out the number of electrons. Help?

How many molecules of oxygen are in 1.75 moles?

 

[just.karl]

10.538 x 10^23 molecules ?

 

[alphysicist]

10.538 x 10^23 molecules ?

I think that's right, so you know how many total molecules there are. Do you see what to do now?

 

[just.karl]

Yeah, then I just divide that by 1 x 10^6 to get the number of electrons, then plug it into the original equation. Thanks! I really appreciate your help

 

[alphysicist]

Yeah, then I just divide that by 1 x 10^6 to get the number of electrons, then plug it into the original equation. Thanks! I really appreciate your help

Glad to help! But remember that you weren't really counting electrons; that number was the number of oxygen molecules that had one more proton than electrons. (But the proton charge magnitude is the same as the electron charge magnitude.)

 

[just.karl]

I thought that I was counting the number of molecules that are missing a electron and what the charge of the gas is without them?

 

[alphysicist]

I thought that I was counting the number of molecules that are missing a electron and what the charge of the gas is without them?

That's exactly right. I must have just misread some of your statements.

 

[just.karl]

lol alright, I probably mis wrote some of the statements. Thanks again!