Demonstrate how conditions affect chemical reactions

endothermic reaction

A reaction in which energy is absorbed; A + B + heat -> <- C + D

Exothermic reaction

A reaction that releases energy in the form of heat; A + B -> <- C + D + heat

What factors can change the condition of a reaction?

Pressure, concentrations of react and products, temperature, and the presence of catalysts -> will change the speed of a reaction

Le Chatelier's Principle

States that if a stress is applied to a system at equilibrium, the system shifts in the direction that relieves the stress.

Catalysts

are chemicals that lower the activation energy required for a chemical reaction to occur; speeds up the process; doesn't change during the reaction and can be reused. Ex. enzymes

A substance that lowers the activation energy is which of the following?

catalyst

Which of the following would slow down a reaction rate?

decreasing the reactants

Increasing concentration of reactants

increases the number of collisions and increases the reaction rate = breaking or creating a bond

Which of the following would increase the forward rate of this gas phase reaction? CO + H2 -> <- CH4 + H2O + heat

increasing the pressure

An enzyme does which of the following to a chemical reaction?

speeds up both the forward and reverse reactions.

For the reaction CO+H2 -> <- CH4 + H2O + heat, equilibrium would favor the reactant side if which of the following occurs?

the temperature decreases