Memory Anchor:

• Super Challenge:

  Stretch:

  Challenge:

Key Questions:

1. How can the rate of a chemical reaction be calculated?
   • The rate of a chemical reaction can be found by measuring the quantity of a reactant used or the quantity of product formed over time: mean rate of reaction = quantity of reactant used / time taken OR mean rate of reaction = quantity of product formed / time taken
2. How is the quantity of a reactant or product measured?
   • The quantity of reactant or product can be measured by the mass in grams or by a volume in cm3.
3. What are the units for rate of reaction?
   • The units of rate of reaction may be given as g/s or cm3/s.
4. (HT only) What is the third unit that is used to measure the rate of reaction in terms of moles?
   • (HT only) The quantity of reactants in terms of moles and units for rate of reaction in mol/s.
5. What would the total amount of a product formed if the rate of reaction is 4g/s and the reaction continues for 3 minutes?
   • The total amount of product formed if the rate of reaction is 4g/s and the reaction continues for 3 minutes would be 540g. This is worked out by: 3 x 60 = 180s 4g x 180s = 540g
6. What key features must be included for graphs showing the quantity of product formed or quantity of reactant used up against time?
   • The key features of a graph to show the quantity of product formed or reactant used up would be an appropriate scale, labels with units and a line of best fit excluding anomalies.
7. How do you draw a tangent on a curve to measure the rate of a reaction on a graph?
   • To draw a tangent on a curve to measure the rate of reaction you should find a straight part of the curve of best fit. The slope of the tangent can be used to measure the rate reaction. The steeper the tangent the faster the rate of the reaction.
8. (HT only) How do you calculate the gradient of a tangent of a curve from a graph?
   • (HT only) To calculate the gradient of a tangent: 1. choose any two points on the line. 2. draw a right-angled triangle with the line as hypotenuse. 3. use the scale on each axis to find the triangle's: vertical length. horizontal length. 4. work out the vertical length ÷ horizontal length. 5. the result is the gradient of the line