A sample of gas has a pressure of 3.2 atmospheres at a temperature of 301 Kelvin. What would be the pressure of the same sample of gas when the temperature is decreased to 285 Kelvin? Show all of the work used to solve this problem.

Question

anonymous · Answer

3.2 for  P1

thomaster · Answer

$\Large\sf \dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}$

P= pressure
T= temperature 

which 3 of these 4 can you fill in?

anonymous · Answer

301 for T1

thomaster · Answer

Yes thats correct

anonymous · Answer

285 for T2

anonymous · Answer

and I guess were trying to figure out the pressure it would be at that temp.

thomaster · Answer

Now do you know how to rework this formula to get P2 in front?

anonymous · Answer

no :/

thomaster · Answer

$\Large\sf \dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}$

what happens when you multiply both sides by T2?

anonymous · Answer

i have no idea honestly

anonymous · Answer

I don't understand how to get it by itself

thomaster · Answer

Alright lets pretend P2 = 1 and T2 = 4

so you'll have $\dfrac{1}{4}$
What happens when you multiply 1/4  by 4?

anonymous · Answer

you have 1

thomaster · Answer

yes, when you multiply a fraction by it's denominator (the bottom one), the answer will be the numerator (the upper one)

So $\large\sf \dfrac{P_2}{T_2}*T_2=P_2$

anonymous · Answer

oh ok

thomaster · Answer

Now we need to multiply the fraction in front of the equal sign too
You will get  $\large\sf \dfrac{P_1}{T_1}*T_2$   because you can't cancel anything out here.

Now we have reworked the formula to be: $\large\sf P_2=\dfrac{P_1}{T_1}*T_2$

Just plug in the numbers and you'll have your answer :)

anonymous · Answer

oh okay let me try it (:

anonymous · Answer

3.02?

anonymous · Answer

3.03*

thomaster · Answer

Yes that's correct, great job!
The pressure at 285 kelvin = 3.03 atm

anonymous · Answer

ah thanks only 9 more till my assignments done haha. i'd appreciate more help but I don't wanna annoy you

thomaster · Answer

I'm here to help, so you won't annoy me with any question :)
First try it yourself and when you're having trouble with the question, you can ask for help here.

anonymous · Answer

okay i'll just write the ones i know I can't do

thomaster · Answer

Don't forget to post it in a new questions :)