# PPM QUESTION

## Recommended Posts

Hello!

I have this question in my textbook, in which I know the answer, yet I cannot figure out how to obtain it: The air has helium 0,0007% (m/m). Convert this concentration into ppm.

##### Share on other sites

Parts per million

0.00007% means 0.00007 per 100 (percent)

Thusly 0.00007/100 = 0.0000007

0.0000007 * 1000000 = 0.7 Parts per million

##### Share on other sites

Thank you so much! I haven't thought of that kind of method. That will help me with a whole bunch of upcoming stuff, I really appreciate it.

##### Share on other sites

I don't think the answer given is correct. Ppm is parts per million. From a percentage concentration, calculating ppm is just a matter of multiplying by 10000 (since % is parts per hundred). Given that, and assuming you've provided the correct number as per the question, I get 7ppm. Can you check that the question states 0.0007% and not 0.00007%?

Parts per million

0.00007% means 0.00007 per 100 (percent)

Thusly 0.00007/100 = 0.0000007

0.0000007 * 1000000 = 0.7 Parts per million

This is correct, but the OP doesn't give 0.00007% as the value.

##### Share on other sites

The question states 0,00007%, and the answer says 0,7ppm.

Sorry I did a typo earlier and typed 0,0007 instead of 0,00007. Thanks for your help so much though!

##### Share on other sites

Parts per million

0.00007% means 0.00007 per 100 (percent)

Thusly 0.00007/100 = 0.0000007

0.0000007 * 1000000 = 0.7 Parts per million

This was prob the easiest way anyone could have explained this nice job. I have favorited this for future use by myself as well. I know I will end up needing this down the road.