Any Chemistry people here? Need some help.

[cody_288]

Can I get some help with my last Chem problem for my Homework due tomorrow morning?

(A) Place the following gases in order of increasing average molecular speed at 300K: CO, SF6 ,H2S, Cl2 , HBr.

(B) Calculate and compare the rms speeds of CO and Cl2 molecules at 300k.

If anyone could help I would really appreciate it. Thanks in advance.

 

[03 black gt]

a) calc their molar masses and the heaviest is slowest...etc..

b) don't remember

 

[cody_288]

Oh... that makes sense , Thank you!


Can anybody help with B?

 

[chevysRslow]

feeling like a dumbass... I used to be good in chemistry but don't remember any of it !!!!!!!!!!!!!!!!!!!!!

 

[cody_288]

Yeah I feel like a dumbass to....

 

[BhavinB]

you can get the RMS velocity by using two equations

the kinetic energy equation: KE=(1/2)*m*v^2
and relating that energy through the average molecular energy equation: ME=3*k*T

where k is the boltzman constant

then solve for v by setting ME=KE.

Have fun!

 

[cody_288]

Thanks!

 

[ampstang]

Too bad I couldn't post earlier. The above solutions are correct. They could have made it tougher by varying the pressures and temperatures between each gas.