Gas calculations

• What equation links the volume of a gas to moles?

  Volume = moles × 24
• What is the volume of 3.5 moles of chlorine gas?

  84 decimeters cubed
• How do you find moles from volume of gas?

  Volume ÷ 24
• What is the volume of 60 decimeters cubed of oxygen in moles?

  2.5 moles
• How do you find the volume from grams of water vapor?

  Convert grams to moles, then use volume equation
• What is the relative formula mass (Mr) of water (H2O)?

  18
• How do you calculate moles from mass and Mr?

  Moles = mass ÷ Mr
• What is the volume of 1.5 moles of water vapor?

  36 decimeters cubed
• What is the limiting reagent in a reaction with excess hydrogen and nitrogen?

  Nitrogen is the limiting reagent
• How many moles of ammonia are produced from 0.75 moles of nitrogen?

  1.5 moles of ammonia
• What is the molar ratio of nitrogen to ammonia?

  1:2
• How do you find the volume of ammonia produced from nitrogen?

  Multiply moles of nitrogen by 2
• What is the volume of ammonia produced from 18 decimeters cubed of nitrogen?

  36 decimeters cubed
• How much hydrogen reacts with 4 decimeters cubed of nitrogen?

  12 decimeters cubed of hydrogen
• When does the equation with the number 24 apply?

  At room temperature and pressure
• What happens to gas volume with changing temperature or pressure?

  Volume changes with temperature or pressure
• What is the only equation needed for gas volume in exams?

  Volume = moles × 24
• What is a limiting reagent in a chemical reaction?

  The reactant that is completely consumed first
• How do you convert grams of a substance to moles?

  Use the formula: moles = mass ÷ Mr
• Why is relative formula mass important in chemistry?

  It helps calculate moles from mass
• How does temperature affect gas volume?

  Higher temperature increases gas volume
• What is the significance of molar ratios in reactions?

  They determine the amounts of products formed