Rates Of Reaction Flashcards
Define reaction rate
Change in the amount of reactants or products per unit time
List five ways in which you can follow the rate of a reaction
PH measurement
Gas volume
Loss of mass
Colour change
Titration
Describe how you can follow the rate of reaction using pH measurement
– Use this method if reactants or product is an acid or base
– Use pH meter or pH probe connected to a datalogger
– PH data can be converted into units of concentration
Rate data will have units of mol dm^-3 time^-1
Describe how you can follow the rate of reaction using gas volumes
– Use this method if gas is given off
- Collect gas in the gas syringe and record volume at regular time intervals
- Units of rate will be volume time^-1
Describe how you will follow the rate of a reaction using mass
– System will lose mass if gas is given off
– Measure at regular intervals using balance
– Units of rate will be mass time^-1
Describe how to follow the rate of reaction using colour change
– Use message if reactants/products is coloured
– Use a calorimeter
– Collect absorbance data and use to calculate concentration using a calibration curve
Describe how you can follow the rate of reaction using a titration method
Monitor concentration of reactant by taking small samples of reaction mixture at regular time intervals and titrating them
Quench each sample of the reaction mixture by adding Deionised water, cooling it, or adding another chemical
How do you work out rate from a concentration time graph?
Work out the gradient
If graph is a curve, draw tangent to curve at a particular time
What is continuous monitoring?
Measuring how the amount of a product or react and changes over the complete course of a reaction
