A sample of a gas occupies 2130 mL at 53.7 degrees celcius and 740 torr. What volume would it occupy at the same pressure and 180 degrees celcius?

Question

Please explain work and show answer please. 

Answer 1

Hey Joanna, 

 

This is a gas laws problem where you can determine which gas law equation to use based off of what you're initially given ( in this case, volume, pressure, and temperature) and what you're asked to find ( change in volume). 

 

The first thing to notice is that pressure does not change throughout the problem; it is held constant. This means we do not have to include it in our calculations. This makes this problem a Charles's Law problem which involves temperature and pressure. 

 

Charles's law states that volume is proportional to temperature. If you increase the temperature of a gas, its volume will also increase. 

 

We are given an initial volume (v1) of 2130 ml and an initial temperature of 53.7 celsius. For these problems, you should convert to the proper units which is Liters for volume and Kelvin for Temperature. When you do this your initial volume (V1) will be 2.13L and your initial temperature (T1) will be (53.7 + 273 = 326.7K)

 

Charles's Law is written as (V1/T1) = (V2/T2). We know our initial values and we know that our temperature increased from 53.7 - 180 celcius, so our T2 = (180+273 = 453K). All that's left is to rearrange our equation to solve for V2 and plug in our values. 

 

V2 = (V1 * T2)/ T1 

 

Since we are increasing the temperature of the gas, our volume should be greater than the initial value (V1). 

 

V2 = (2.13L * 453K) / (326.7K)  = 2.95L    (notice that V2 is larger which matches our prediction based off of Charles's Law).

 

Hope this helps!