The correct calculation for the % of oxygen in air:

% oxygen = ​( (a)   ​ (b)   ​ (c)   ) x 100

• change in volume
• total starting volume
• final volume

Initial volume = 50.0 cm³

Final volume = 40.5 cm³

Calculate the % of oxygen in air to 1 decimal place

Initial volume = 25 cm³

Final volume = 20.2 cm³

Calculate the % of oxygen in air to 1 decimal place

Initial volume = 48.0 cm³

Final volume = 38.2 cm³

Calculate the % of oxygen in air to 1 decimal place

Initial volume = 9.5 cm³

Final volume = 7.5 cm³

Calculate the % of oxygen in air to 1 decimal place

Initial volume of syringe = 90.0 cm³

Final volume of syringe = 62.3 cm³

Volume of air in connecting tube = 10.0 cm³

Volume of air in conical flask = 50.0 cm³

Calculate the % of oxygen in air to 1 decimal place

Initial volume of syringe = 75.0 cm³

Final volume of syringe = 34.6 cm³

Volume of air in connecting tube = 15.0 cm³

Volume of air in conical flask = 110.0 cm³

Calculate the % of oxygen in air to 1 decimal place

Initial volume of syringe = 50.0 cm³

Final volume of syringe = 26.2 cm³

Volume of air in connecting tube = 12.0 cm³

Volume of air in conical flask = 58.0 cm³

Calculate the % of oxygen in air to 1 decimal place

Initial volume of syringe = 50.0 cm³

Final volume of syringe = 14.3 cm³

Volume of air in connecting tube = 18.0 cm³

Volume of air in conical flask = 107.0 cm³

Calculate the % of oxygen in air to 1 decimal place

Which of the following are possible reasons for the % of oxygen calculated being less than expected

• Not left long enough

• left for too long

• not enough iron filings

• too many iron filings