CL 10- rates of reaction Flashcards
1
Q
rate of reaction
definition
A
change in concentration of a reactant or product in a given time
1
Q
explain how increasing the concentration affects the rate
A
- increasing the concentration increases the number of particles in a given volume
- this increases the number of collisions per unit time with energy equal to or greater than the activation energy
- so the rate of reaction increases
2
Q
explain how increasing the pressure affects the rate
A
- increasing the pressure increases the the number of particles in a given volume
- this increases the number of collisions per unit time with energy equal to or greater than the activation energy
- so the rate of reaction increases
3
Q
catalyst
definition
A
increases the rate of reaction by providing an alternate pathway with a lower activation energy
4
Q
homogenous catalyst
A
in the same physical state as the reactants
5
Q
heterogenous catalyst
A
in a different physical state to the reactants
6
Q
importance of catalysts
environmentally and economically
A
- less fuel used which cuts costs and increases profitablility
- less fossil fuels used which reduces carbon dioxide emissions which is a greenhouse gas and linked to global warming
7
Q
2 ways of monitoring rate of reaction that produces a gas
A
- measure the volume of gas produced over time by using a gas syringe, or collecting the gas in a measuring cylinder over water
- measure the loss in mass over time by placing the open reaction vessel on a balance
8
Q
boltzmann distribution increase in temperature
what does diagram look like, explanation
A
- at higher temperature, the curve is lower and shifted to the right
- a greater proportion of molecules exceed the activation energy
9
Q
boltzmann distribution with catalyst
A
- original Ea further along x-axis
- new Ea closer to y-axis
- greater proportion of molecules exceed the new lower activation energy
