Volume of Gases

Question 1

What is the equation for number of moles of gas?

Answer 1

Number of moles of gas = Volume of gas (dm³) / 24dm³

Question 2

What is the volume of 1 mole of any gas at room temperature?

Answer 2

The volume of 1 mole of any gas is 24dm³ at room temperature (20 degrees C) and pressure (1 atmosphere). Equal numbers of moles of any gas occupy the same volume. 24dm³ per mole is known as the molar gas volume.

Question 3

Complete this exam question.
“If 25 cm³ of a solution of sodium hydroxide is exactly neutralized by 13.5 cm³ of 0.6mol/dm³ hydrochloric acid, what is the concentration of the alkali?
HCl + NaOH”

Answer 3

C = M/V

HCl
Concentration: 0.6mol/dm³
Volume: 13.5cm³ = 13.5 / 1000 = 0.0135dm³
Moles: M = C X V 
0.6 x 0.0135 = 0.0081 mol

NaOH
Concentration: C = M/V = 0.0081/0.025 = 0.324ml/dm³
Volume: 25 cm³ = 25 / 1000 = 0.025dm³
Moles: Cause it is a 1:1 ratio it is the same moles.
0.0081 mol

Question 4

What is the formula for concentration?

Answer 4

Concentration (mol/dm3) = Number of moles/volume of solution