Core practical T4 L4
What techniques can be used to find the rate of a reaction
1.Precipitate
2.Change is mass
3.Volume of gas given off
Describe the steps of the teqnique prectpitation to mesure the rate of a reaction
!Only works between 2 transparent solutions to form an opaque solution i.e precipitate (fine solid particles in the solution)
1. Place the conical flask containing 2 solution on a peice of paper with a cross.
2.The time it takes to not see the cross indicates the rate of reaction.
Explain the limits of using a precipitate reaction to find the rate of a reaction
Subjective(people may decide that the cross is dissapearing at different times)
Describe the technique change in mass for measuring the rate of a reaction
1.Measure mass before
2.Bung with cotton wool to prevent anything but gas escaping
3.Measure mass after
State a limitation of using change of mass as a technique for measuring rate of reaction
Gas could be harmful
Describe the technique volume of gas given off for measuring the rate of a reaction
1.Collect gas in a syringe (make sure airtight to prevent loss in gas)
2.The more gas given off in a set time the faster the reaction has occurred
What is the dependant and independent variables on a speed of reaction chart
Dependant-Y
Independent-X