Question

Question #5174b

Answer 1

The mass will be 4429 g

Explanation:

Use the ideal gas law to solve this problem: `PV=nRT`

This law specifies the possible conditions for a sample of gas, and makes it possible for us to find a fourth condition when values are given for the other three.

Here, we know the pressure, P is 135.0 atm. The volume, V is 200.0 L and the temperaure T is 24.00 °C, or better as 297K.

Thus, we can solve for the missing value, which is `n`, the gas quantity in moles.

`n = (PV)/(RT)`

You must be careful to choose a value for the gas constant `R` that matches the units given in the problem. Specifically, since the pressure is in atmospheres, we use `R= 0.0821 ("L atm")/(K" mol")`

`n = ((135)(200))/((0.0821)(297)) = 1107.3` moles

Now, multiply by the molar mass of helium (4 g) and this answer is reported as a mass.