Amount of Substance Calculations

1.  Propane burns in oxygen according to the equation below

C3H8 + 5O2 → 3CO2 + 4H2O

What is the minimum volume of oxygen gas needed for the complete combustion of 25 dm3 of propane at stp? (5 marks)

2.  A volume of 112cm3 of carbon dioxide is produced when limestone is reacted with an excess of dilute hydrochloric acid. Given that the equation for the reaction is

CaCO3 + 2HCl → CaCl2 + H2O + CO2

Calculate the mass of limestone required in g, if the reaction is carried out at stp.

(5 marks)

3.  During fermentation using yeast, 1.8g of glucose (C6H12O6) can be converted into 0.92g of ethanol (C2H6O) and 448cm3 CO2 measured at stp.

  1. Calculate the number of moles of glucose used in this experiment (1)
  2. Calculate the number of moles of ethanol and carbon dioxide produced in this experiment (3)
  3. Hence write a balanced equation showing the fermentation reaction (1)

4. An organic compound Y (Mr = 58) has this percentage composition by mass :

Carbon = 62.04% Hydrogen = 10.41% Oxygen = 27.55%

Calculate the molecular formula of Y (5)

Total = 20

Amount of Substance Calculations

1.  Propane burns in oxygen according to the equation below

C3H8 + 5O2 → 3CO2 + 4H2O

What is the minimum volume of oxygen gas needed for the complete combustion of 25 dm3 of propane at stp? (5 marks)

2.  A volume of 112cm3 of carbon dioxide is produced when limestone is reacted with an excess of dilute hydrochloric acid. Given that the equation for the reaction is

CaCO3 + 2HCl → CaCl2 + H2O + CO2

Calculate the mass of limestone required in g, if the reaction is carried out at stp.

(5 marks)

3.  During fermentation using yeast, 1.8g of glucose (C6H12O6) can be converted into 0.92g of ethanol (C2H6O) and 448cm3 CO2 measured at stp.

  1. Calculate the number of moles of glucose used in this experiment (1)
  2. Calculate the number of moles of ethanol and carbon dioxide produced in this experiment (3)
  3. Hence write a balanced equation showing the fermentation reaction (1)

4. An organic compound Y (Mr = 58) has this percentage composition by mass :

Carbon = 62.04% Hydrogen = 10.41% Oxygen = 27.55%

Calculate the molecular formula of Y (5)

Total = 20