Clicker Questions Chapters 13, 14, 15

1. Clicker QuestionsChapters 13, 14, 15 Dana and Michelle Chatellier University of Delaware

2. The rule of “like dissolves like” refers to similarities between _______ of miscible liquids. molecular weights shapes intermolecular attractive forces d. densities

3. Which of the following compounds is miscible with water? CH3OH CH4 C6H6 d. CH3CH2OCH2CH3

4. Which of the compounds below is the LEAST miscible with water? CH3OH CH3CH2OH CH3CH2CH2OH d. CH3CH2CH2CH2OH

5. _______ Law says that the solubility of a gas in a liquid increases as the pressure of the gas increases. Boyle’s Charles’s Henry’s d. Raoult’s

6. _______ Law says that the vapor pressure of a solution is proportional to the mole fraction of the solvent. Boyle’s Charles’s Henry’s d. Raoult’s

7. The molality of a solution is defined as the amount of solute (in moles) divided by the volume of the solution (in liters). mass of the solvent (in kilograms). mass of the solution (in kilograms). d. total number of moles.

8. In general, as the temperature of a solution increases, the solubility of a gaseous solute increases. decreases. remains unchanged. d. varies from gas to gas.

9. What is the freezing point of a 2.00 m aqueous solution of sucrose? The value of Kf for water is 1.86 degrees C/molal. –3.72 degrees C –1.86 degrees C +1.86 degrees C d. +3.72 degrees C

10. What is the vapor pressure of a solution containing 0.500 mol of glucose and 5.000 mol of water at 29 degrees C? PH2O @ 29°C = 30.04 torr 30.0 Torr 27.3 Torr 25.0 Torr d. 2.7 Torr

11. A 0.100 molal solution of which compound below will have the lowest freezing point? NaCl CaCl2 KI d. LiNO3

12. What is the molecular weight of adrenaline if 0.64 grams of adrenaline dissolved in 36.0 g of CCl4 raises the boiling point by 0.49 degrees Celsius? Kb= 4.95 °C/m 180 g/mole b. 360 g/mole c. 720 g/mole d. 1800 g/mole

13. Light scattering by colloidally dispersed particles is an example of the _______ effect. Tyndall Raoult Hall d. Meissner

14. The rate of a reaction can be increased by increasing reactant concentrations. increasing the temperature. adding a suitable catalyst. d. All of the above

15. Over time, the rate of most chemical reactions tends to _______. increase decrease remain constant d. oscillate

16. If tripling the concentration of reactant A multiplies the rate by a factor of nine, the reaction is _______ order in A. zeroth first second d. third

17. Reaction: A + B  C + DRate = k[A][B]The overall order of this reaction is first. second. third. d. fourth.

18. Reaction: W + X  Y + ZRate = k[W]The order of this reaction with respect to X is zeroth. first. second. d. third.

19. The time required for the concentration of a reactant to be reduced to half of its initial value is called the midpoint of the reaction. equivalence point of the reaction. half-rate of the reaction. d. half-life of the reaction.

20. If k is the rate constant of a first-order reaction, the half-life of the reaction is: 0.693/k 0.693k k/2 d. 2k

21. The value of the rate constant (k) for a first-order reaction is 0.010 sec–1. What is the half-life of this reaction? 10 seconds 69 seconds 100 seconds d. 690 seconds

22. A + B  products, Rate = k[A],k = 0.010 sec–1, Initial [A] = .100 M, Final [A] = .00100 M How long will this take? 69 seconds 138 seconds 460 seconds d. 690 seconds

23. Rate = k[A]2, Initial [A] = 0.100 M, k = 0.0214 M–1 sec–1What is the half-life of this second-order reaction? 69 seconds 138 seconds 460 seconds d. 690 seconds

24. Rate = k[A]2, Initial [A] = 0.100 M, k = 0.0214 M–1 sec–1After 1.00 hour, what is the concentration of reactant A? 0.0500 M 0.0250 M 0.0189 M d. 0.0115 M

25. The minimum energy that a collision between molecules must have for a reaction to occur is called the initial energy. internal energy. external energy. d. energy of activation.

26. At 298 K, k = 1.36  10–7 sec–1.At 323 K, k = 2.72  10–6 sec–1.The energy of activation for this reaction is 100 kJ/mole. 310 kJ/mole. 690 kJ/mole. d. 1000 kJ/mole.

27. The rate-determining step is the _______ step in a reaction mechanism. first last c. fastest d. slowest

28. Adding a catalyst increases the rate of a chemical reaction because the presence of the catalyst increases molecular velocities. increases molecular collisions. decreases energy of activation. d. All of the above

29. At equilibrium, the rate of the forward reaction is _______ the rate of the reverse reaction. equal to slower than faster than d. the reverse of

30. The reaction quotient Q is usually represented by [reactants] / [products]. [products] / [reactants]. [reactants]  [products]. d. [reactants] + [products].

31. If the value of the equilibrium constant is large, then _______ will mostly be present at equilibrium. reactants products catalysts d. shrapnel

32. If the value of the equilibrium constant is small, then _______ will mostly be present at equilibrium. reactants products catalysts d. shrapnel

33. Q = the reaction quotientK = the equilibrium constantAt equilibrium, which is true? Q > K Q < K Q = K d. Q2 = K

34. Equilibrium constants typically have units of M. M2. M1–. d. None of the above

35. Reaction quotients for heterogeneous equilibria do not include concentrations of pure liquids. pure solids. Both of the above d. Neither of the above

36. HA ⇋H+ + A–[HA] = 1.65  10–2 M and [H+] = [A–] = 5.44  10–4 M at equilibrium. Kc = _______. 1.79  10–2 1.79  10–3 1.79  10–4 d. 1.79  10–5

37. KP = KC when the reaction is at equilibrium. the reaction is exothermic. all of the gases present are at the same pressure. d. the number of moles of gas on both sides of the balanced equation is the same.

38. CO2 + H2⇋CO + H2OIf all species are gases and H2 is added, the concentration of CO at equilibrium will increase. decrease. remain unchanged. d. disappear.

39. CO2 + H2⇋CO + H2OIf all species are gases and H2O is added, the equilibrium concentration of CO will increase. will decrease. will remain unchanged. d. will disappear.

40. CO2 + H2⇋CO + H2OIf all species are gases and CO2 is removed, the [CO] at equilibrium will increase. decrease. remain unchanged. d. disappear.

41. CO2 + H2⇋CO + H2OIncreasing the temperature of this endothermic reaction will _______ [CO] at equilibrium. increase decrease not change d. eradicate

42. CO2 + H2⇋CO + H2OIf all species are gases and the container is compressed, the amount of CO will increase. decrease. remain unchanged. d. vanish.

43. CO2 + H2⇋CO + H2OAdding a catalyst to this reaction will cause the [CO] at equilibrium to increase. decrease. remain unchanged. d. cease to exist.