Reaction rates

Question 1

What is rate of reaction

Answer 1

Is the speed at which reactants are chemically converted into products

Question 2

3 steps of collision theory

Answer 2

1. Particles must collide
2. Particles must collide with correct orientation
3. Particles must collide with sufficient energy to overcome the minimum activation energy

Question 3

Exothermic energy diagrams energy of products is

Answer 3

Lower than the reactants

Question 4

Endothermic energy diagrams energy of products is

Answer 4

Higher than the reactants

Question 5

How does nature of reactants affect reaction rate

Answer 5

A chemical reaction that has less bond breaking and bond forming will be faster than a more complex reaction

Question 6

How does concentration affect reaction rate

Answer 6

Increase in concentration increases rate of reaction, more particles per unit volume increase frequency of collisions. increases frequency of particles that have successful collisions with sufficient energy and correct orientation

Question 7

How does pressure/volume affect reaction rate

Answer 7

Increaseing pressure or decreasing volume increases the rate of reaction. Same number of particles exposed to smaller volume, particles are closer. this leads to an increased frequency of collisions and a greater proportion of successful collisions.

Question 8

how does surface area affect reaction rates

Answer 8

Increase in surface area of reactants increase rate of reaction, increase surface area increases number of reactant particles exposed and available for collisions

Question 9

How does agitation increase reaction rates

Answer 9

Increases reaction rate by creating a movement in fluid. increasing KE, reacting particles are more exposed for collisions.

Question 10

How does temperature increase reaction rate

Answer 10

An increase in temperature can increase rate of chemical reaction, more KE so particles vibrate, increase velocity of particles, which cuases more collisions, greater propotion of particles that have energy greater than activation energy

Question 11

How does addition of a catalyst effect reaction rate

Answer 11

A catalyst increases reaction rate by providing an alternate reaction pathway that has a lower activation energy, this increases the proportion of particles that have sufficient energy to overcome the actvation energy.

Catalyst does not lower activation energy