Academic Subjects
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Chemistry
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General Chemistry
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Gases ➤
Calculating Pressure Of Gas Heated To 402 K

A sample of gas has an initial volume of 2.4 L at a pressure of 843 mm Hg and a temperature of 304 K.
If the gas is heated to a temperature of 402 K and therefore expands to 4.7 L, what is its final pressure (in mm Hg)?



We're dealing with a gas here, so let's apply the Ideal Gas Law

pV = nRT

Since we're not interested in the type of gas, i.e. moles,
we'll ignore both n and R and end up with

pV = nRT

changein

Now, we can set up a ratio between
the initial and the final state of this gas

(pinitial)(Vinitial) / Tinitial
=
(pfinal)(Vfinal) / Tfinal

 chemistry is most amusing

Let's plug in the info provided


(843 mm Hg)(2.5 L) / 304 K
=
(pfinal)(4.7 L) / 402 K

pressure



And now we solve for x

pfinal =
(843 mm Hginitial)(2.5 Linitial) (402 K) / (304 K)(4.7 L)



pfinal = 592 mm Hg

The final pressure of this gas is 592 mm Hg
considering sig figs, it is 5.9 x 102 mm Hg