rate of reaction

Question 1

how do you work out the mean rate of reaction

Answer 1

amount of reactant used OR product formed
———————————-
time taken

Question 2

how the rate of reaction be found

Answer 2

• measuring the amounts of reactants used
• measuring the amount of products formed
• meandering time taken for a reaction mixture to become opaque or change colour

Question 3

measuring the amount of reactants used:

Answer 3

• if one of the products is a gas, measure the mass in grams of the mixture before and after the reaction takes place and the time it takes for it to happen
• mass of mixture will decrease
• g/s

Question 4

measuring the amount of products formed

Answer 4

-gas, measure total volume produced cm^3 with a gas syringe and the time it takes for the reaction to happen

Question 5

measuring the time it takes for a mixture to become opaque or change colour:

Answer 5

• how long it takes to change colour

- rate of reaction 1 divided time taken for solution to change colour

Question 6

what’s the collision theory

Answer 6

-chemical reactions only occur when reacting particles collide with each other with sufficient energy

Question 7

what is activation energy

Answer 7

minimum amount of energy required to cause a reaction

Question 8

five factors that affect rate of reaction:

Answer 8

• temp
• concentration
• SA
• catalysts
• pressure

Question 9

temperature

Answer 9

-in a hot reaction mixture particles move more quickly, collide more often with greater energy, collisions are successful

Question 10

concentration

Answer 10

• at higher concentrations, particles are closer together , so they collide more often->more successful collisions
• increasing pressure of reacting gases increases frequency of collision

Question 11

SA

Answer 11

• small pieces of a solid reactant have a large SA in relation to their volume
• more particles are exposed and available for collisions, so more collisions and a faster reaction

Question 12

concentration of a reactant calculation

Answer 12

-amount
—————-
vol of reaction mixture

measured in mol/dm^3

Question 13

By increasing the concentration and reactions, pressure of reacting gases, SA of solid reactants, temperature, how does this affect the rate of reaction?

Answer 13

increases FREQUENCY OF SUCCESSFUL COLLISIONS and so increases rate of reaction