Tesla 4th Quarter Mastery Exam- General Chemistry 2

How will crushing a solid into a powder increase reaction rate?

• The activation energy barrier will be lowered.

• The orientation of colliding particles will be improved.

• The particles will collide with more energy.

• The powdered form has more surface area.

For the reaction 1A + 2B + 1C --> 2D + 1E, the rate law is: rate =k [B]²[C]¹ Which of the following statements is false:

• the reaction is first order in [A]

• the reaction is second order in [B]

• the reaction is first order in [C]

• the reaction is third order overall

What refers to the peak of the energy diagram for a chemical reaction?

• Activated Complex

• Collision Theory

• Activation Energy

• Law of Conservation of Mass

Which of the following statements best describes Collision Theory?

• Atoms or molecules must collide with sufficient amount of energy in order to react.

• Catalyst can be recovered unchanged at the end of the process

• Increasing the concentration of a reactant increases the rate of reaction.

• Smaller pieces have a greater surface area, thus, providing much greater contact among the reactants and effecting more collisions.

Which of the following statements about catalysts is false:

• catalysts do not appear in the balanced equation

• catalysts reduce the activation energy for a reaction

• biological catalysts are called enzymes

• since catalysts are recycled, even a small amount of catalyst can accelerate a reaction

Which represents a decrease in entropy?

• sublimation of CO2

• boiling water

• NaCl dissolving in water

• condensation of steam on cold glass

Predict the signs of ΔH , ΔS and ΔG for the reaction: Mg(s) --> Mg(g)

• Δ H = +

  Δ S = +

  Δ G = -

  (At all temperature)

• Δ H = +

  Δ S = +

  Δ G = -

  (At low temperature)

• Δ H = -

  Δ S = +

  Δ G = -

  (all temperature)

• Δ H = +

  Δ S = +

  Δ G = -

  (At high temperature)

The second law of thermodynamics states that:

• The entropy of a perfect crystal is zero at 0 K.

• The entropy of the universe is constant.

• The energy of the universe is increasing.

• The entropy of the universe is increasing.

9. At constant pressure, the following reaction 2NO₂(g) → N₂O₄(g) is exothermic. The reaction (as written) is

• always spontaneous

• spontaneous at low temperatures, but not high temperatures

• spontaneous at high temperatures, but not low temperatures

• never spontaneous

Choose the correct correlation between Gibbs free energy and spontaneity.

• a reaction to be spontaneous, ΔG has to be positive.

• a reaction to be spontaneous, ΔG has to be zero

• reaction to be spontaneous, ΔG has to be negative.

• no correlation between ΔG and spontaneity