Question

Ideal Gas Law Problems1. What volume will 12 g of oxygen gas (O2) occupy at 25 C and a pressure of 52.7 kPa?

Answer 1

17.6 L.

Step-by-step explanation:

What is given?

Mass of oxygen (O2) = 12 g.

Molar mass of O2 = 32 g/mol.

Temperature (T) = 25 °C + 273 = 298 K.

Pressure (P)= 52.7 kPa

R = 0.082 L*atm/mol*K.

What do we need? Volume.

Step-by-step solution:

We have to use the following formula of ideal gas law:

`PV=nRT.`

Where P is pressure, V is volume, n is the number ofmoles, R is the constant of ideal gas and T is tthe emperature ion the Kelvin scale.

But we have to convert 12 g of O2 in moles, so let's do this using the molar mass of O2:

`12\text{ g O}_2\cdot\frac{1\text{ mol O}_2}{32\text{ g O}_2}=0.375\text{ moles O}_2.`

Now, we have to find the pressure in units of atm. Remember that 1 atm equals 101.3 kPa:

`52.7\text{ kPa}\cdot\frac{1\text{ }atm}{101.3\text{ kPa}}=0.520\text{ atm.}`

And the final step is to solve for 'V' which is volume and replace the given data:

`V=(nRT)/(P)=\frac{0.375\text{ moles}\cdot0.082(L\cdot atm)/(mol\cdot K)\cdot298K}{0.52\text{ atm}}=17.6\text{ L.}`

The volume of oxygen gas would be 17.6 L.