How many moles of gas are present in a gas cylinder at #18*atm# at a temperature of #123# #""^@C#?

Question

Naomi Aronson · Accepted Answer

Approx. #25-30*mol#

Using the Ideal Gas Equation as a source.

#n=(PV)/(RT)=(18.4*atmxx50.0*L)/(0.0821*L*atm*K^-1*mol^-1xx400*K)=#

#??"moles"#. What mass does this represent?

If the caretaker is allowing compressed gas cylinders to get that hot, he really needs to be beaten. I would really like to talk to him about it.

Kai Bowman · Answer

undefined To find the number of moles of gas present in the cylinder, you can use the ideal gas law equation:

$$PV = nRT$$

Where:
- $P$ is the pressure in atm,
- $V$ is the volume in liters,
- $n$ is the number of moles of gas,
- $R$ is the ideal gas constant ($0.0821 \, \text{atm} \cdot \text{L/mol} \cdot \text{K}$),
- $T$ is the temperature in Kelvin.

First, convert the given temperature from Celsius to Kelvin:

$$T(K) = T(^@C) + 273.15$$

$$T(K) = 123 ^@C + 273.15 = 396.15 K$$

Now, rearrange the ideal gas law equation to solve for $n$:

$$n = \frac{PV}{RT}$$

Substitute the given values:

$$n = \frac{(18 \, \text{atm})V}{(0.0821 \, \text{atm} \cdot \text{L/mol} \cdot \text{K})(396.15 \, \text{K})}$$

You would also need the volume of the gas cylinder to calculate the number of moles.