# Question #5e940

##### 1 Answer

Here's what I got.

#### Explanation:

Since your didn't provide enough information to allow for a direct answer, I'll try to take a more general approach and show you how to solve similar problems in the future.

Your tool of choice for **any** ideal gas problem is the ideal gas law equation. You can use it to derive all the other gas law equation.

#color(blue)(PV = nRT)" "# , where

**absolute temperature** of the gas, i.e. the temperature expressed in *Kelvin*.

Now, the problem starts like this

A sample of ammonia gas in a non-rigid container occupies a volume of#"4.00 L"# at a.certain temperatureandpressure

This tells you two important things

thenumber of molesof gas isprobablyconstantthe volume of the gas isnot constant

We can now distinguish **three possible scenarios**

Pressureandtemperaturechange

Let's say that the ammonia gas is initially kept at a pressure

#PV = nRT implies (PV)/T = overbrace(n * R)^(color(green)("constant"))#

This means that you can equate the initial state of the gas with a final state by writing

#color(blue)((P_1V_1)/T_1 = (P_2V_2)/T_2) -># the combined gas law equation

This equation implies that **both** the temperature and the pressure of the gas **change** from

To get the new volume of the gas, rearrange this equation to solve for

#V_2 = P_1/P_2 * T_2/T_1 * V_1#

At this point, you would use the new values for pressure and temperature,

Pressurechanges, buttemperatureremains constant

Once again, start from the ideal gas law equation. This time the pressure of the gas changes, but its temperature is kept constant.

#PV = overbrace(n * R * T)^(color(green)("constant"))#

You will thus have

#color(blue)(P_1V_1 = P_2V_2 -># the equation for Boyle's Law

This time, the new volume of the gas will be

#V_2 = P_1/P_2 * V_1#

Finally, the third possible scenario

Pressureis kept constant, buttemperaturechanges

Starting from the ideal gas law equation

#PV = nRT implies V/T = overbrace((nR)/P)^(color(green)("constant"))#

You will thus have

#color(blue)(V_1/T_1 = V_2/T_2) -># the equation for Charles' Law

This time, the new volume of the gas will be

#V_2 = T_2/T_1 * V_1#

This is how you can figure out which gas law to use. Remember, the ideal gas law equation can be used as the **starting point** for all of them.