General Chemistry Questions & Answers CH-13

General Chemistry Questions & Answers CH-13 Activated complex - CORRECT ANSWER- A chemical species with partially broken and partially formed bonds; Always high in energy because of its partial bonds Also referred to as the transition state Activation energy (Ea) - CORRECT ANSWER- The extra energy needed to start the molecule reacting; The amount of energy needed to convert reactants into an activated complex Activation energy of slowest step - CORRECT ANSWER- Slowest step has largest activation energy After 1 half-life - CORRECT ANSWER- 50% remains and 50% has reacted/decayed After 2 half-lives - CORRECT ANSWER- 25% remains and 75% has reacted/decayed After 3 half-lives - CORRECT ANSWER- 12.5% remains and 87.5% has reacted/decayed After 4 half lives - CORRECT ANSWER- 6.25% remains and 93.75% has reacted/decayed Aliquots - CORRECT ANSWER- Samples from the reaction mixture which are drawn off at specific times during the reactions, and quantities analysis is performed (including titration for one of the components and gravimetric analysis) Average rate - CORRECT ANSWER- The change in measured concentrations in any particular time period (linear approximation of a curve); The larger the time interval, the more the average rate deviates from the instantaneous raye Bimoleciular step - CORRECT ANSWER- Involves two particles, but they may be the same kind of particle Catalysts - CORRECT ANSWER- Substances that affect the rate of a reaction without being consumes; Work by providing an alternative mechanism for the reaction with a lower activation energy; insured in an early mechanism step and then made in a later step Chemical kinetics - CORRECT ANSWER- the study of the factors that affect the rates of chemical reactions, such as temperature Collision frequency - CORRECT ANSWER- Number of collisions which happen per second; More collisions per second means more collisions is ions can be effective and lead to product formation; Therefore the higher the collision frequency, the higher the reaction rate Collision theory of kinetics - CORRECT ANSWER- For a reaction to take place,r enacting molecules must collide with each other, but whether or not this collision leads to a reaction