Ways to measure the rate of reaction
- How quickly the reactants are used up
- How quickly the product is formed
Rate of reaction = How quickly the reactants are used up /How quickly the product is formed
Time
Precipitation – how long it takes for a mark to disappear if the reaction gets cloudy (remember: the paper with the cross on it experiment) – issue: it is subjective to when the cross disappears because people will see it differently
Change in mass – most accurate way of measuring rate of reaction. If you put the reaction on the scales and measure how long it takes to weigh less. (see page 108) – Issue: can’t use it for really dangerous experiments because the gas has to be released into the air. If the reaction gets to hot you can lose not only the gas but the liquid as well, and you don’t want this because all you want to measure is the gas being given off.
Use of a gas syringe – (see page 108) the faster the volume of gas released and pushes the syringe out the faster the rate of reaction – issue: if the reaction is too explosive and blows the syringe out you can’t really measure.