In all of the questions that follow remember your units:


Pressure equals Pascal = Pa
Volume equals cubic metres = m3

Temperature equals Kelvin = K

n equals moles = mol

R equals the gas constant = 8.31 JK-1mol-1


Q. 1.25 g of an unknown gas occupied 923 cm³ at a pressure of 102 kPa and a temperature of 290 K. Find the relative formula mass of the gas.


Q. Find the mass of 200 cm³ of carbon monoxide (CO) at 17°C and a pressure of 98,900 Pascal (C = 12, O = 16).


Q. Calculate the volume occupied of 0.1g hydrogen gas (H2) at 293 K and a pressure of 100 kPa (H = 1)


Q. The hydrocarbon gas Ethane burns in oxygen according to the equation:


(a) What volume of Oxygen would be required to burn 1 dm3 of Ethane?


(b) What volume of Carbon Dioxide would be produced?


Q. 20 cm³ of a hydrocarbon needed 90 cm³ of oxygen for complete combustion. 60 cm³ of carbon dioxide was produced. All volumes were measured at room temperature and pressure. Find the formula of the hydrocarbon.


Q. 2.76 g of a particular carbonate X2CO3 were treated with an excess of dilute hydrochloric acid, and the carbon dioxide involved was collected and measured. 480 cm³ was produced at room temperature and pressure.


Calculate the following:


(a) the number of moles of the carbonate used in the experiment


(b) the mass of 1 mole of the carbonate


(c) the relative atomic mass of the element X



Q.  (a) Calculate the number of moles of gas molecules in a laboratory with a volume of 969 m³ (not including any volume taken up by benches and so forth) at a temperature of 290 K and a pressure of 99.5 kPa.


      (b) Assuming that the area inside the lab contains 0.93% Argon by volume, calculate the number of moles of organ in the lab and hence calculate the number of argon atoms in the lab.


Take the gas constant R to be 8.31 JK-1mol-1 and the Avogadro constant to be 6.02×1023 mol-1



Q. Sulphur dioxide can be removed from flue gases by reacting it with calcium carbonate (limestone). If any flue gas contains 1% sulphur dioxide by volume, what mass of calcium carbonate would be needed to remove the sulphur dioxide from 1000 m³ of the flue gas.


The equation for the reaction between calcium carbonate and sulphur dioxide is as follows:



(C = 12, O = 16, Ca = 40)


Q. 10 cm³ of an unknown hydrocarbon was sparked with 100 cm³ of Oxygen (an excess). When the resulting gases were cooled back to the original room temperature, they had a volume of 75 cm³. Exposure of these gases to Sodium Hydroxide solution reduced the volume to 35 cm³.


From this information find the formula of the hydrocarbon.



Go to >> Solutions <<

Back to >> Ideal Gas Law <<