How Consitions Affect Chemical Reactions 3.4 Flashcards
Which of the following explains why increasing the concentration of reactants causes the reaction rate to increase?
A Increasing concentration raises the temperature of the reaction, which speeds up the reaction.
B Crowding makes molecules fragile, so bonds are more likely to break.
C It increases the likelihood that reactants will come into contact with one another.
D Increasing concentration raises the pH of the reaction, which speeds up the reaction.
C It increases the likelihood that reactants will come into contact with one another.
Which of the following best describes activation energy?
A It is the difference in energy between the reactants and products.
B It is the rate of the reaction.
C It is the minimum energy needed to get the reaction started.
D It is the energy stored in the chemical bonds of the product.
It shifts the equilibrium to the left.
The reaction of Nz and H2 forming NH; is exothermic but does not occur at room temperature. It is usually conducted at 400° C. Which of the following best describes the effect increasing temperature has on the reaction?
N2 + 3H2- 2NHs+ energy
The high temperature increases the rate of the forward reaction.
The high temperature lowers the rate of collisions between reactants.
It causes other compounds such as hydrozoic acid to form.
It shifts the equilibrium to the left.
D It shifts the equilibrium to the left.
Which of the following can be determined from the reaction shown below?
CuSO4 + Zn -+ ZnSO4 + Cu
A It goes to completion.
B It is an equilibrium reaction.
C It is reversible.
D Zn is a catalyst.
A It goes to completion.
Which of the following statements is correct?
A Enzymes perturb the equilibrium of a reaction.
B Any enzyme can catalyze a large number of reactions.
C Enzymes make reactions go to completion.
D Enzymes lower the activation energy.
D Enzymes lower the activation energy.
You set up two flasks to carry out the same endothermic double replacement reaction in each flask, flask A and flask B. You heat flask A to 95 flask B to 63° C. You run the reaction for 10 min and then analyze the amounts of products and reactants in each flask. Which of the followin, differences, if any, might you observe between the two flasks?
A Flasks A and B have the same amount of products formed;
B Flask A has more products than flask B.
C Flask A has less products than flask B.
D Flask A generates more heat than flask
B Flask A has more products than flask B.
A catalyst increases the rate of a reaction by doing which of the following?
A Raising the pressure
B Lowering the activation energy
C Lowering the temperature
D Acting as a reactant
B Lowering the activation energy
Ethylene (C2H4) reacts with hydrogen and forms ethane (CH6). However, in the absence of a metal such as nickel, little if any product forms.
C2Н4 + H2 = С2H6
Which of the following would describe the role of nickel in the reaction?
A Nickel removes product.
B Nickel is a catalyst.
C Nickel raises the product energy.
D Nickel increases the reactant concentration.
B Nickel is a catalyst.
Which of the following would result if the H2 concentration is increased?
CO + 2H2 = СНзОН
A CH OH would be the new product.
B No change would occur.
C The reaction would shift to the right.
D The reaction would stop.
The reaction would shift to the right.
Which of the following statements best describes why the reaction shown changes direction in the lungs compared to the direction in respiring tissue?
CO2 + H20 = H2C03
A CO, is high in respiring tissue, but low in the lungs.
COz is low in respiring tissue, but high in the lungs.
Respiring tissue consumes H2O3; but the lungs do not.
The lungs have less water.
CO2, is high in respiring tissue, but low in the lungs.
- For the reaction CO + H2 =* CH4 + H2O + heat, equilibrium would favor the reactant side if which of the following occurs?
A. H2O is added
B. The temperature decreases
C. CO is added
D. CHa is removed
H20 added
- Which of the following would increase the forward rate of this gas phase reaction?
CO + H2 = CHA + H20 + heat
A. Adding CO
B. Increasing the temperature
C. Adding H20
D. Increasing the pressure
Adding CO
- A substance that lowers the activation energy is which of the following?
A. Reactant
B. Product
C. Catalyst
D. Time
Catalyst
- Which of the following would slow down a reaction rate?
A. Increasing the temperature
B. Adding enzymes
C. Decreasing the pressure
D. Decreasing the reactants
Decreasing pressure
Decreasing the reactants
- An enzyme does which of the following to a chemica reaction?
A. Shifts the reaction to the right
B. Shifts the reaction to the left
C. Speeds up both the forward and reverse reactions
D. Changes the reaction from one that is at equilibrium to one that goes to completion
Speeds up both the forward and reverse reactions
