AP Chemistry Unit 6- Kinetics

What will change then curve of a collision graph?

A higher temperature will make the curve of the graph longer while a lower temperature will make the curve of the graph taller

Which of the following best helps explain why an increase in temperature increase the rate of a chemical reaction?

At higher temperatures, high-energy collisions happen more frequently

The rate of reaction between CaCO3 and CH3COOH is determined by measuring the volume generated at 25C and 1 atm as a function of time. Which of the following experimental conditions in most likey to increase the rate of gas production?

Decreasing the particle size of the CaCO3 by grinding it into a fine powder

Increasing the temperature of a reaction increases the reaction rate by: I. increasing frequency of collisions II. increasing the force with which molecules collide III. decreasing the potential engery of collisions

I and II only

Which of the following statements is/are true in relation to rate laws? I. A rate law must be determined experimentally and cannot be deduced from a chemical equation alone II. Zero-order have rate constants equal to rates III. A linear plot can be obtained for a first-order reaction by plotting the reciprocal of the concentration of reactant (y-axis) against time (x-axis)

I only

The reaction of a tertiary haloalkane (represented by RX below) with hydroxide ions is found to follow the mechanism: Step one: RX->R+X (slow) Step two: R+OH->ROH (fast) If step one is found to be the slow step in the mechanism, which of the following statements is true? I. The reaction will be found to be first-order with respect to RX II. The reaction has an intermediate that is represented by R III. The reaction rate is independent of the concentration of hydroxide ions

I, II, and III only

For a reaction that is first order with respect to [D] and second order with respect to [E], which of the following will result in no change to the overall reaction rate?

Increasing [D] by a factor of four and halving [E]

Why does increasing the temperature of the collision curve speed up the reaction?

It allows for more energetic collisions

What is activation energy?

It is the energy change from the starting position to the highest energy point on the potential energy diagram

What does a catalyst do to the activation energy?

It lowers it

What would be the effect on the reaction rate if the solution of C25H30N3 is diluted by water?

It would be lower

How does a catalyst affect the Arrhenius Equation?

K will increase

N2O+CO->N2+CO2 The rate of the reaction represented above increases significantly in the presense of Pd. Which of the following best explains this observation?

One of the reactants binds on the surface of Pd, which introduces an alternative reaction pathway with a lower activation energy

What affects the activation energy of a reaction?

Temperature

What is collision theory?

The more succesful collisions there are, the faster the reaction rate

Cu+4HNO3->Cu(NO3)+2NO2+2H20 In one student's experiment the reaction proceeded at a much slower rate than it did in the other students' experiments. Which of the following could explain the slower reaction rate?

The student used a 1.5M solution of HNO3 instead of 15.8M solution of HNO3

NO+NO3->2NO2 rate=k[NO][NO3] The reaction represented above is a single reaction. The observed reaction rate is only a small fraction of the calculated collision rate. Which of the following best explains the discrepancy?

The two reactant particles must collide with a particular orientation in order to react

What must happen for collisions to be successdul?

They must have sufficient energy to overcome the activation energy barrier and the molecules must have the right orientation/geometry in order to allow the bonds to rearrange in the required manner

PCl5<--> PCl3+Cl2 The temperature of PCl5 is help constant until it reaches equilibrium with its decomposition products. As the reaction progresses toward equilibrium, the rate of the foward reaction

decreases to become a constant nonzero rate at equilibrium

For the reactoin whose rate law is: rate=k[X], a plot of which of the following is a straight line?

ln [X] versus time