Question

A sample of hydrogen gas has a volume of 8560. mL at standard temperature and a pressure
of 1.50 atm. Calculate the number of moles of H, present in this gas sample.

Answer 1

Answer: 5.26 moles

Explanation:

Given that:

Volume of hydrogen gas V = 8560mL

(since 1000 mL = 1dm3

8560mL = 8560/1000= 8.56dm3)

Standard temperature T = 25°C

Convert temperature in Celsius to Kelvin

(25°C + 273 = 298K)

Pressure P = 1.5atm

Number of moles of hydrogen = ?

Note that Molar gas constant R is a constant with a value of 0.0082 ATM dm3 K-1 mol-1

Then, apply ideal gas equation

pV = nRT

1.5 atm x 8.56dm3 = n x (0.0082 atm dm3 K-1 mol-1 x 298K)

12.84atm dm3 = n x 2.44atm dm3 mol-1

n = (12.84atm dm3 / 2.44atm dm3 mol-1)

n = 5.26 moles

Thus, there are 5.26 moles of Hydrogen, H present in this gas sample.