Reacting mass calcutions

• Reacting mass


  The amount of matter an object contains. Mass is measured in kilograms (kg) or grams (g).
• Reactant


  A substance that reacts together with another substance to form products during a chemical reaction.
• Product


  A substance formed in a chemical reaction.
• Simple ratio


  The relative sizes of two or more numbers, shown as whole numbers. For example, 1:2 or 3:2.
• Calculating reacting masses and product masses


  1. Write out the balanced symbol equation

  2. Underline the two substances you are interested in

  3. Write the given mass of a substance under its formula

  4. Work out the total relative formula mass (Mr) for each substance (the one you know and the one you are trying to find out)

  5. Calculate: unknown mass = (known mass ÷ total Mr of known substance) × total Mr of unknown substance
• The mass of a product or reactant can be calculated using the balanced equation