Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Kinetics
| Question | Answer |
|---|---|
| What are chemical kinetics? | Chemical kinetics is the study of the rates of chemical reactions and the factors that affect them. |
| How is the rate of a chemical reaction defined? | The rate of a chemical reaction is defined as the change in concentration per unit time. |
| How is the rate of a chemical reaction usually expressed in units? | mol L-1 s-1. |
| How is the average rate calculated? | Average rate = -(delta)[A]/(delta)t. |
| What are the factors that affect the rates of reaction? | Nature of the reaction, concentration of the reactants, temperature, physical state of the reactants, presence of catalysts, and action of light. |
| Explain the rate law for a first order reaction. | The rate is directly proportional to the concentration of the reactant. |
| If the concentration of reactant is doubled, and the rate doubles, what does it mean for the reaction? | The reaction is a first-order reaction. |
| Explain the rate law for a second order reaction. | The rate is proportional to the square of the concentration. |
| If the concentration of reactant is doubled, and the rate increases by a factor of 4, what does it mean for the reaction? | The reaction is a second-order reaction. |
| Explain the rate law for a zero order reaction. | The rate does not depend on concentration. |
| Express first order reaction in an equation. | rate = [A]. |
| Express second order reaction in an equation. | rate = [A]2. |
| What are the units of a first order rate constant? | s-1. |
| What are the units of a zero order rate constant? | mol L-1 s-1. |
| What is the rate constant? | The rate constant is the proportionality constant. |
| What symbol is given to the rate constant? | k. |
| How is the rate constant measured (in experiments)? | Rate constant is determined by the slope of a concentration vs. time graph, which is created by measuring concentrations at various times in a reaction. |
| Define the stopped-flow technique. | Solutions are forced from syringes into a mixing chamber, and stopped after a very short period of time (see: few milliseconds). |
| What is the half-life of a reactant? | The time taken for a concentration of the reactant to fall to half of its initial value. |
| What symbol is used to express half-life? | t1/2. |
| What is the Arrhenius equation? | k = Ae-(Ea/RT). |
| What is the Arrhenius equation used for? | For calculating the rate of reaction. |
| Explain what the symbols in the Arrhenius equation stand for? | R is the gas constant, T is the temperature, Ea is the activation energy, and A is the pre-exponential factor. |
| What are the units for the symbols in the Arrhenius equation? | R = J K-1 mol-1, T = K, Ea = J mol-1. |
| What are oscillating reactions? | Many reactions do not proceed smoothly, but generate products in bursts. |
| What are catalysts? | Catalysts are substances that speed up a reaction without being consumed in the overall process. |
| What are homogeneous catalysts? | A catalyst that works in the same phase (gas, liquid, or solid) as the reaction. |
| What are heterogeneous catalysts? | A catalyst that works in a different phase. |
| Explain how the presence of catalysts affects the reaction rate. | A catalyst provides an alternative pathway of lower activation energy, making the rate of reaction faster. |
Created by:
Smileyfeng
Popular Chemistry sets