Question

A piston cylinder holds a 2.50 L volume of air at 325.0 K. The cylinder holds the gas at 3.00 atm pressure.How many moles of air are present in the cylinder under these conditions?___ moles

Answer 1

0.281 moles.

Step-by-step explanation:

What is given?

Volume (V) = 2.50 L.

Temperature (T) = 325.0 K.

Pressure (P) = 3.00 atm.

R = 0.082 L*atm/mol*K.

Step-by-step solution:

This is an ideal gas law problem. The ideal gas law is a single equation which relates the pressure, volume, temperature, and the number of moles of an ideal gas. The formula of the ideal gas is given by the following:

`PV=nRT,`

where P is pressure, V is volume, n is the number of moles, R is the constant of ideal gas, and T is temperature.

We want to find the number of moles of air present in the cylinder, so we have to solve for 'n' and replace the given data, like this:

`n=(PV)/(RT)=\frac{3.00\text{ atm}\cdot2.50L}{0.082(L\cdot atm)/(mol\cdot K)\cdot325.0\text{ K}}=0.2814\text{ moles }\approx0.281\text{ moles.}`

The answer is that we have 0.281 moles of the present air.