I need help !!!!!!!!!!! Plz
1) How will increasing the surface area of one or more reactants affect the reaction rate of a system?



A It will change the products of the reaction.



B It will speed up the reaction.



C It will slow down the reaction.



D It will have no effect on the reaction.


2)Which change will usually speed the reaction rate of a chemical system?


A increase the concentration of a reactant



B decrease the temperature of the system



C decrease the pressure of a system



D increase the concentration a product


3) Some metals found in a car’s exhaust system speed up a chemical reaction but are not used up.


How do these metals work to speed up the reaction?



A They act as catalysts.



B They increase the pressure in the system.



C They increase the temperature of the system.



D They increase the concentration of reactants.


4) How does a catalyst affect the activation energy of a reaction?



A A catalyst increases the activation energy needed for a reaction.



B A catalyst does not affect the activation energy of a reaction.



C A catalyst decreases the activation energy needed for a reaction.



D A catalyst eliminates the need for activation energy.


5) Which theory explains the increase in reaction rate caused by raising the temperature or raising the pressure of a system?


A potential energy theory



B activation energy theory



C surface area theory



D collision theory