Rate of reaction
Change in concentration of reactant it product per unit time
What happens as reaction proceeds?
Fewer collisions and rate slows down
How can rate be determined from the graph?
Rate equals slope of curve, measured by drawing tangent, gradient calculated
How can acid/base reactions rate be measured? P
pH change by titration or pH probe
How can gas producing reaction rate be measured
Change or volume or pressure, loss in mass of reactant
Measure reaction with visual changes?
Formation of precipitate and colour change
How does concentration affect rate?
Greater concentration means more collisions per second so faster reaction
What happens is to rate if concentration of zero order reactant is increased?
Unaffected
What happens is to rate if concentration of first order reactant is increased by 2?
3?
Increased 2 times
Increased 3 times
What happens is to rate if concentration of second order reactant is increased by 2?
3?
4 times
9 times
What is rate equation?
Shows relationship between rate if reaction and concentrations of reactant raises to powers of their orders
What can be determined from concentration time graphs?
Determine order with respect to reactant from shape of graph
What shape graph is zero order reaction? Concentration over time
Concentration decreases at constant rate, half life decreases with time
What shape is a first order graph? Concentration over time
Concentration halves in equal time intervals, half life is constant
What shape is second order graph? Concentration over time
Concentration decreases rapidly, but rate of decrease then slows down . Half life increases with time
Rate voncentartion graph shape of zero order
Straight as rate unaffected by changes in concentration
Rate concentration graph shape of first order
Straight know diagonal, increases by same amonbt
Rate voncentartion graph shape of second order?
Curved
How can orders be determined by different initial amounts of concentration?
Compare the experiments by looking at rate of reaction and initial amount of each reactant
What does value of k mean?
Large value is fast reaction
Small value is slow reaction
How does temperature affect k?
Increase in temp gives more KE to particles, so faster rate, increasing k
Rate doubles per 10 degrees
What is rate determining step?
Slowest step in a reaction mechanism, obstacle for process, products can only be made as fast as they can get through slow step, overall reaction can be no faster that this step, if a reactant is involved in equation it is part of rate determining step, order tells you how many particles are involved
