Problem: Final volume of Gas

[TexasFluoride]

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Here is a problem from Topscore Exam #1.

What is the final volume of a gas at 70K if it is initially at 280K and 10ML?

The answer is 2.5mL.

Here is how I worked out the problem (please tell me why I am wrong):

(70K)(V)=(280K)(10ML)
70V=2800
V=40mL

 

[Bio Dental Mom]

I think your equation is set up wrong.

Think: PV=nRT so, if you set up the eqn where R is equal for two gases you get:

P1V1/n1T1 = P2V2/n2T2, so you are using the temperature in place of pressure, you need to be putting that in the denominator, so after plugging and chugging the numbers you get (and canceling out terms that would be common on both sides) and rearranging everything you get:

70*10/280 = 2.5

I hope that helps.

 

[DQLEUCD]

Here is a problem from Topscore Exam #1.

What is the final volume of a gas at 70K if it is initially at 280K and 10ML?

The answer is 2.5mL.

Here is how I worked out the problem (please tell me why I am wrong):

(70K)(V)=(280K)(10ML)
70V=2800
V=40mL

Yea wrong rule. that's M1V1=M2V2 rule. It's V1/T1 = V2/T2. You should also konw the different laws like boyles, charles and avagadro's for this one.

 

[chromosome21]

M1V1 = M2V2 is used to find dilute concentration of SOLUTIONS. Here, we are finding final volume of a GAS.

 

[nyr201]

Here is a problem from Topscore Exam #1.

What is the final volume of a gas at 70K if it is initially at 280K and 10ML?

The answer is 2.5mL.

Here is how I worked out the problem (please tell me why I am wrong):

(70K)(V)=(280K)(10ML)
70V=2800
V=40mL

theres an easier way to do this since u know the relationship between P and V theyre inversely related and V and T are directly related so here we have T drop by a factor of 4 (just do 28/7= 4) so then V will drop by a factor of 4 so then V will be 1/4 the value of 10mL which = 2.5 mL

no need for formulas, as long as u know ur PV=nRT relationships these are cake

 

[m3lowrider]

theres an easier way to do this since u know the relationship between P and V theyre inversely related and V and T are directly related so here we have T drop by a factor of 4 (just do 28/7= 4) so then V will drop by a factor of 4 so then P will be 1/4 the value of 10mL which = 2.5 mL

no need for formulas, as long as u know ur PV=nRT relationships these are cake

When you say P will be 1/4 the value of 10ml which = 2.5 ml, do you mean "V"?

 

[nyr201]

When you say P will be 1/4 the value of 10ml which = 2.5 ml, do you mean "V"?

yeah sorry typo ill edit it