Question

Part 1.)

Select all of the correct statements about reaction rates from the choices below.

1. The lower the rate of a reaction the longer it takes to reach completion.
2. As a reaction progresses its rate goes up.
3. Catalysts decrease reaction rates.
4. A balanced chemical reaction is necessary to relate the rate of reaction to the concentration of a reactant.
5. Reaction rates increase as concentrations of homogeneous catalysts increase.
6. The higher the rate of a reaction the longer it takes to reach completion.
7. Reaction rates decrease with increasing temperature.

Part 2.)

Select all of the correct statements about equilibrium from the choices below.

1. At equilibrium the rates of forward and reverse reactions are equal.
2. As a reaction proceeds backwards toward equilibrium the reverse rate drops.
3. Reactants are transformed into products even at equilibrium.
4. At equilibrium concentrations of reactants and products stay constant.
5. At equilibrium the forward rate equals zero.
6. As a reaction proceeds backwards toward equilibrium the reactant concentrations rise.

Part 3.)

Select all of the correct statements about the relative acid strengths of pairs of acids from the choices below.

1. HCl is a stronger acid than H₂S because Cl is more electronegative than S.
2. H₂S is a stronger acid than H₂Se because S is more electronegative than Se.
3. H₂AsO₄^- is a stronger acid than H₃AsO₄ because it has more charge (is more unstable).
4. H₂O is a stronger acid than H₂S because O is more electronegative than S.
5. H₂O is a stronger acid than H₂Se because O is more electronegative than Se.
6. HClO₄ is a stronger acid than HClO₃ because it has more oxygens surrounding the central Cl atom.

Part 4.)

Choose all of the statements from below which are true about oxidation and reduction.

1. Oxidation and reduction are opposite processes with respect to bookkeeping electrons.
2. Oxidation is what happens when an element in a substance gains electrons.
3. Electrons appear on the right side of an oxidation half reaction.
4. An oxidant is an oxidizing agent, which becomes reduced during the course of a redox reaction.
5. Reduction is what happens when an element in a substance loses electrons.
6. Electrons appear on the left side of a reduction half reaction.
A reductant is a reducing agent, which becomes reduced during the course of a redox reaction.

Part 5.)

Choose all of the processes from below which describe changes which are independent of the path by which the change occurs.

1. the elevation increase experienced by a traveller travelling from Grand Isle, LA to Denver, Colorado
2. the amount of work required to build a house
3. the enthalpy released by the combustion of a gallon of gasoline
4. the latitude increase experienced by a traveller travelling from Baton Rouge, LA to Anchorage, Alaska
5. the odometer mileage increase observed by a traveller travelling from Louisiana to Canada
6. the heat generated by the body of a student during a chemistry exam
7. the change in the score of a football game as the game progresses

Answer 1

Part 1.) Correct statements:

1. The lower the rate of a reaction the longer it takes to reach completion.

4. A balanced chemical reaction is necessary to relate the rate of reaction to the concentration of a reactant.

5. Reaction rates increase as concentrations of homogeneous catalysts increase.

Part 2.) Correct statements:

1. At equilibrium the rates of forward and reverse reactions are equal.

3. Reactants are transformed into products even at equilibrium.

6. As a reaction proceeds backwards toward equilibrium the reactant concentrations rise.

Part 3.) Correct statements:

1. HCl is a stronger acid than H₂S because Cl is more electronegative than S.
2. H₂S is a stronger acid than H₂Se because S is more electronegative than Se.
4. H₂O is a stronger acid than H₂S because O is more electronegative than S.
5. H₂O is a stronger acid than H₂Se because O is more electronegative than Se.
6. HClO₄ is a stronger acid than HClO₃ because it has more oxygens surrounding the central Cl atom.

Part 4.) True statements:

1. Oxidation and reduction are opposite processes with respect to bookkeeping electrons.
3. Electrons appear on the right side of an oxidation half reaction.
4. An oxidant is an oxidizing agent, which becomes reduced during the course of a redox reaction.
6. Electrons appear on the left side of a reduction half reaction.

Part 5.) Independent:

1. the elevation increase experienced by a traveller travelling from Grand Isle, LA to Denver, Colorado
4. the latitude increase experienced by a traveller travelling from Baton Rouge, LA to Anchorage, Alaska
6. the heat generated by the body of a student during a chemistry exam