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Hello, can somebody please help me with this word problem? Thanks.

Hello, can somebody please help me with this word problem? Thanks.-example-1

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We are given that this is an ideal gas, and that the volume and presumably the number of moles of gas are constant. We can use Gay-Lussac's Law, which describes volume and pressure. We have that pressure is directly proportional to volume. For a change in a gas, we can write the equation as

(P_i)/(T_i) = (P_f)/(T_f),
where i denotes initial and f denotes final.

We have that
T_i=600 \ K,
T_f=800 \ K, and
P_f=30 \ atm. We need to find
P_i. To do so, let's first rearrange Gay-Lussac's equation to solve for
P_i.


(P_i)/(T_i) = (P_f)/(T_f) \\\\P_iT_f=P_fT_i\\\\P_i= (P_fT_i)/(T_f)

Now, we plug in our values to get
P_i.


P_i= (P_fT_i)/(T_f)=(30\ atm \ 600 \ K)/(800 \ K) = 22.5 \ atm.

This seems like a reasonable value, because as temperature goes up, pressure goes up, and an increase in temperature corresponds to an increase in pressure.

Technically, you were given values with only one significant figure, so you can only report the value as
20 \ atm, but this depends on how your instructor usually does these problems!

User Rakesh Soni
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