Chemhw6.2
These questions deal with collision theory, activation energy, and catalysts. REMEMBER: PERIOD# followed by FIRST & LAST NAME
- 1.A catalyst is added to a system at equilibrium. If the temperature remains constant, the activation energy of the forward reaction
- A.
Decreases
- B.
Increases
- C.
Remains the same
- 2.Base your answer to this question on the information below. A student wishes to investigate how the reaction rate changes with a change in concentration of HCl(aq). Given the reaction: Zn(s) + HCl(aq) → H2(g) + ZnCl2(aq) Identify one other variable that might affect the rate and should be held constant during this investigation. [1]
- 3.Base your answer to this question on the information below. A student wishes to investigate how the reaction rate changes with a change in concentration of HCl(aq). Given the reaction: Zn(s) + HCl(aq) → H2(g) + ZnCl2(aq) Describe the effect of increasing the concentration of HCl(aq) on the reaction rate and justify your response in terms of collision theory. [1] (HINT: 2 word answer)
- 4.Given the reaction: S(s) + O2(g) → SO2(g) + energy Which diagram best represents the potential energy changes for this reaction?
- A.
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- B.
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- C.
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- D.
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- 5.In most aqueous reactions as temperature increases, the effectiveness of collisions between reacting particles
- A.
Increases
- B.
Decreases
- C.
Remains the same
- 6.Given the reaction at 25°C: Zn(s) + 2 HCl(aq) → ZnCl2(aq) + H2(g) The rate of this reaction can be increased by using 5.0 grams of powdered zinc instead of a 5.0-gram strip of zinc because the powdered zinc has
- A.
Lower kinetic energy
- B.
Lower concentration
- C.
More surface area
- D.
More zinc atoms
- 7.Given the reaction: N2(g) + O2(g) + 182.6 kJ → 2 NO(g) Which change would cause an immediate increase in the rate of the forward reaction?
- A.
Increasing the concentration of NO(g)
- B.
Increasing the concentration of N2(g)
- C.
Decreasing the reaction temperature
- D.
Decreasing the reaction pressure
- 8.At STP, which 4.0-gram zinc sample will react fastest with dilute hydrochloric acid?
- A.
Bar
- B.
Lump
- C.
Powdered
- D.
Sheet metal
- 9.Which information about a chemical reaction is provided by a potential energy diagram?
- A.
The oxidation states of the reactants and products
- B.
The average kinetic energy of the reactants and products
- C.
The change in solubility of the reacting substances
- D.
The energy released or absorbed during the reaction
- 10.A catalyst works by
- A.
Increasing the potential energy of the reactants
- B.
Increasing the energy released during a reaction
- C.
Decreasing the potential energy of the products
- D.
Decreasing the activation energy required for a reaction
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