Destroyer Genchem # 59

[topdent1]

Advertisement - Members don't see this ad

Why doesn't the temperature change along with the density? If you look at the formula P(MW)=DRT, you see that MW is proportional with D and T, yet the answer says that if MW changes, only D will change.

 

[TeamGuo]

not in this case, you are adding the same mol amount of gas in, they are identical gases except with different MW.

Temperature would rise if you put in more of the other gas, hence increasing pressure too. In this case, P and T stays same. 😀

 

[topdent1]

I don't get it. I'm just following simple mathematic rules of proportionality. It should work.

 

[jdent]

Assume constant temperature unless told differently.

 

[mistero]

I had the question as topdent. Based on the density formula, it does make sense that temperture would be affected by MW. I still don't understand why temperature doesn't change.
At first I thought that PV=nRT shows that MW doesn't affect temperature b/c it isn't in the formula, but then I realized that it is in the formula b/c it is part of how to calculate n.
Can anyone answer the question?

 

[mistero]

The only possible explanation as to why the temperature won't change (this is a wild geuss) is that maybe any change in MW has a corresponding change in density as shown by the previous formula. If these changes are always proportional (I have no idea if they are or not proportional), then no change would occur in any of the other variables in the equation.