$$$ Quiz $$$ Reaction Rates and Equilibrium

What are the units for a reaction rate? M/s, molarity per second, concentration per second

What is the highest energy stage of a reaction called? transition state or activated complex

How does a catalyst speed up a reaction? Lowers activation energy barrier

When reacting molecules collide with each other, do they always form a reaction? No, improper orientation, not enough KE

What is a calorie or joule? Unit of heat (q)

What are the four factors we discussed that affect the rate of reaction? Temperature, concentration, particle size, and use of catalyst

What does an inhibitor do? Interferes with the action of a catalyst

At equilibrium, what can you say about reactants and products? The rates of production of both are equal.

What does the double arrow mean in chemistry? There is a forward and reverse reaction

“If a stress is applied to a system in dynamic equilibrium, the system changes in a way that relieves the stress”, is known as _________. Le Chatelier’s Principle

According to Le Chatelier’s Principle, if you remove products from a reaction at equilibrium, what will happen to the reactants? The reactants will react more to offset the loss of products, thus becoming lower themselves

True or False. If you have more gas molecules on the left-side of a reaction, and you increase the pressure, the equilibrium will shift to the right. True

True or False. If K eq = 1 x 10 -5, then products are favored. False

Solve the K eq expression for the following reaction. Mg(s) + 2HCl(aq)  MgCl 2 (aq) + H 2 (g) K eq = [MgC l 2 ][H 2 ]/[HC l ] 2

Write an expression for the solubility product constant, K sp, for the following dissolving process. NaC l (s)  Na + (aq) + C l - (aq) K sp = [Na + ][C l - ]

What is the equation for Gibb’s Free Energy?  G =  H-T  S

What is  S and what does it measure? Entropy, it measures disorder In a system

What is  H and what does it measure? Enthalpy, it measures the heat in a reaction

If the heat of a reaction,  H, is kJ, what can you say about the reaction? Exothermic, gives off heat when reactants are combined

If you take a solid and liquid, and mix them to produce a gas, what can you say about the reaction in terms of “chaos theory”?  S is positive Entropy obviously increased

What can you say about a reaction that has +  G? Nonspontaneous

What three variables can tell you whether a reaction will occur on its own or need outside help? Enthalpy,  H Entropy,  S Temperature of system

If the  H of a reaction is positive then the reaction is _______. endothermic

What is the enthalpy change in a chemical reaction known as? Heat of reaction,  H

Can you do the following? -Write out a K eq expression when given a random reaction -Then plug in given concentration values to actually calculate K eq. - Then interpret what the K eq value actually means?

Can you do the following? -If you are given K sp, can you calculate individual ion concentrations?