Segment 2 Exam Review (V22; ID: 5657)

This review is neither a replica of the exam nor does it contain every concept in the module or what may be on the exam.  It is always best practice to review all lessons and assessments. Resubmitting is a great way to review/learn and improve your grade.   The number in parenthesis corresponds to the lesson for that question.  Please reach out to your instructor with any questions (answer key).    The Element Song!

Regular: There are 20 multiple choice questions on the exam. There are no free response/essay questions.

Honors:  There are 25 multiple choice questions on the exam. There are no free response/essay questions.

Multiple Choice:

1. Which of the following is a correct step to convert 3.56 moles calcium to atoms of calcium? (5.01)

1. Multiply 3.56 moles Ca by its molar mass
2. Divide 3.56 moles Ca by its molar mass
3. Multiply 3.56 by Avogadro’s number                        
4. Divide  3.56 by Avogadro’s number
   

2. How many moles are in 356 grams of gold, Au? (5.01)

1. 70117 moles Au                        c.  2.56 moles Au
2. 1.81 moles Au                        d. 52300 moles Au

3. Calculate the number of molecules in 25.6 grams of carbon dioxide, CO2.  (5.02)

1. 3.50 X 1023 molecules CO2                c. 6.78  X 1026 molecules CO2
2. 1.87 X 10-211 molecules CO2                d. 1.54 X 1025 molecules CO2

4. How many grams of water are in 2.45 X 1024 molecules of water? (5.02)

1. 54.5 g H2O                         c. 1.47 g H2O 
2. 2.65 X 1048 g H2O                 d. 73.3 g H2O 
   

5. If we use four moles of Na2S for the following reaction, which of the following will be true? (5.04)  

Na2S  + MgCl2 → 2NaCl +  MgS

3. Eight moles of sodium chloride will be formed
4. Four moles of magnesium sulfide will be formed
5. It will require four moles of magnesium chloride
6. All are correct

6. When 25.6 grams of sodium reacts with an excess of water, as shown in the chemical equation below, how many moles of sodium hydroxide will be produced? (5.04)

Na(s) + H2O (l) → NaOH (aq) + H2(g)

7. 588 moles NaOH                c.  0.557 moles NaOH
8. 1.11 moles NaOH                d.  2.22 moles NaOH

7. If 52.4 grams of magnesium oxide reacts with 86.5 grams of hydrochloric acid according to the following reaction, what is the maximum amount of  magnesium chloride that can be formed?  (5.06)

 MgO + HCl →  MgCl2 + H2O

9. 124 g MgCl2                        c. 113 g MgCl2
10. 245 g MgCl2                        d. 75 MgCl2

8. Refer to question #7.  When we calculate the maximum amount of the product we can make, what term do we refer to that as? (5.06)

1. Percent Yield                        c. Actual Yield
2. Theoretical Yield                d. Yield

9. Which of the following is an incorrect rearrangement of the percent yield formula? (5.07)

1. Actual yield =  (percent yield)(theoretical yield)

                                              100

2. Percent yield =     actual yield       X   100

                         theoretical yield

3. Theoretical yield  =   actual yield    X 100

                                   percent yield

4. Actual Yield =     percent yield      X 100

                           theoretical yield

10. During a laboratory experiment, a 4.68 g sample of potassium chlorate was  decomposed to form potassium chloride and oxygen gas. After reaction, the percent yield of potassium chloride was calculated to be 83.5%. What was the actual yield from the reaction?  (5.07)  2KClO3 (s)  → 2KCl (s)  +  3O2 (g)

1. 2.85 g KCl                                c. 120%
2. 74%                                        d. 2.38 g KCl

11. If the reaction of 4.75 moles of hydrogen gas with excess nitrogen gas produced an 86.5% yield of ammonia, what was the actual yield of ammonia?  (5.07)

2H2 + N2 → 3NH3

3. 3.66 moles NH3                                c. 3.17 moles NH3
4. 2.74 moles NH3                                d. 1.37 moles NH3

12. Compare kinetic and potential energy; include an example of each. (6.01)  

13. Define temperature. Give three units to measure temperature. (6.01)  

14. Identify the characteristics of a solid, liquid, gas and plasma. (6.02)

15. Put the states of matter in order in terms of increasing kinetic energy  (6.02)

1. Solid < liquid < gas < plasma                c. Solid < gas < liquid < plasma
2. Gas < liquid < gas < plasma                d. Plasma < gas < liquid < solid

16. Put the states of matter in order in terms of increasing attractive forces (6.02)

1. Solid < liquid < gas                         c. Liquid < solid < gas
2. gas < liquid < solid                         d. Not enough information

17. Which of the following is true for solids compared to liquids? (6.02)

1. Their speed of motion is higher
2. Their attractive forces are greater
3. Their kinetic energy is higher
4. Their ability to bond is greater

18. Referring to the diagram to the right, which of the following is true at 4 minutes? (6.03)

1. All of the water is a solid                
2. Most of the solid has melted into a liquid
3. All of the water is a liquid                
4. The temperature of the liquid is higher than the solid

19. What happens to the particles of a gas when the gas changes into a solid? (6.03)

1. The attractive forces between them decreases
2. They speed up
3. They move in constant, random motion
4. Their volume decreases

20. Which of the following are held constant in both Charles’ and Boyle’s Laws? (6.04)

1. Pressure and number of moles        c. Number of moles are volume
2. Temperature and pressure                d. Number of moles

21. A sample of gas has a pressure of 1.8 atmospheres at a temperature of 275 Kelvin. What would be the pressure of the same sample of gas when the temperature is decreased to 260 Kelvin? (6.04) Note: Be able to use all gas laws to solve for any variable.

1. 1.7 atm                                c. 3.5  atm
2. 5.7 atm                                d. 10.4 atm

22. A sample of nitrogen gas has a volume of 0.75 L at 32 °C and 3.2 atm. What is the volume when the pressure changes to 2.7 atm and temperature is constant?

1. Not enough information        c. 0.63 L
2. 071 L                                d. 0.89 L

23. Which of the following is true for the diagram below? (7.01) Note: be able to label and describe potential energy diagrams for both endothermic and exothermic reactions.

3. It is an endothermic reaction because the reactants have more energy than the products
4. It is an exothermic reaction because there is an increase in enthalpy
5. There is no activation energy needed for this reaction
6. The enthalpy decreases so this is an exothermic reaction.

24. Which of the following is true for activation energy? (7.01)

1. It is the energy released or absorbed in the reaction
2. It is the energy required to start a reaction
3. Not all reactions require activation energy
4. Activation energy cannot be measured

25. Which of the following is an example of an endothermic process? (7.01)

1. Freezing water                        c.  Photosynthesis
2. Rusting of iron                d. Combustion reactions

26. Refer to the diagram on the right.  

1. It is endothermic because heat is flowing in
2. It is exothermic because heat is flowing in
3. It can not be classified without knowing what the liquid is

27. What is the sign for enthalpy in an exothermic reaction? (7.02)

1. Negative because the products have more energy than the reactants
2. Positive because the reactants have more energy than the products
3. Negative because the reactants have more energy than the products
4. Positive because the products have less energy than the reactants

28. 45.8 grams of copper requires 1172 J of heat to reach a final temperature of 100.5 ℃.  What was the initial temperature? Specific heat of copper is 0.385 J/g℃. (7.02)

1. 66.5                                 c. 34.0
2. 122                                 d. 75.2

29. How do we determine the change of total enthalpy? (7.02)

1. ΔH = Hreactants - Hproducts
2. ΔH = Activation Energy - (Hreactants - Hproducts)
3. ΔH = Hproducts - Hreactants 
4. ΔH = Activation Energy - (Hproducts - Hreactants)

30. Which of the following is the best description of how a catalyst affects the rate of reaction?  (7.04)

1. Catalysts can lower activation energy which means reactions require less activation energy to begin.

5. Catalysts increase the temperature which allows for more reactions to occur
6. Catalysts do not affect rate of a reaction
7. Catalysts increase the energy of reaction which allows for more reactions to occur.

31. 20 grams of magnesium were placed in a flask with 100 mL of sulfuric acid. Which one of the following would produce 100 mL of hydrogen gas the fastest?  (7.04)

1. Removing 5 g of magnesium
2. Removing 50 mL of hydrogen gas
3. Increasing the temperature by 10℃
4. Decreasing temperature by 10℃

32. List three factors that can increase the rate of reaction. Please explain these factors using the collision theory.  (7.04) 

33. The rate of a chemical reaction may be defined as (7.04)

1. the change in concentration of any one of the reactants or products
2. the time it takes for the reaction to be completed
3. the change in concentration of any one of the reactants only
4. the change in concentration of any one of the products only

34. Which of the following best describes whether or not all reactions achieve equilibrium? (7.05)

1. Yes, all reactions can as long as the concentrations remain the same
2. No, it must be a reversible reaction in order to reach equilibrium
3. Yes, as long as there are reactants left in the vessel
4. No because some are exothermic

35. Which of the following is true about a system at equilibrium? (7.05)

1. Rates of the forward and reverse reactions are complete.
2. Forward and reverse reactions continue reacting.
3. The reactions are complete.
4. Concentrations of the components are equal

36. What property allows water to get into the pores of a paper towel and move up, against gravity? (8.01)

1. Surface tension                                c.  Polarity
2. Capillary action                                d.  Cohesion

37. Why is water considered the Universal Solvent? (8.01)

1. It has a high polarity                        c. It is a climate regulator
2. It has a low surface tension                d.  It has strong cohesion forces

38. What is the molarity of a solution prepared by dissolving 20.4 g of sodium hydroxide in enough water to make a total of 255 mL of solution? (8.02)

1. 0.0800 M                                c. 0.00200 M
2. 1.67 M                                        d.  3.34 M

39. How many moles of Na2CO3 are there in 10.0 L of 2.00 M solution?(8.02)

1. 20.0 mol                                        c. 10.0 mol
2. 5.00 mol                                        d. 2.00 mol
   

40. What happens to a solution if we add more water to it? (8.02)

1. It becomes more acidic                        c.  It becomes more diluted
2. It becomes more concentrated                d.  It reaches equilibrium

41. If you dilute 175 mL of a 1.6 M solution of LiCl to 1.0 L, determine the new concentration of the solution. (8.02)

1. 280 M                                        c.  0.28 M
2. 9.1 M                                        d.   0.11 M

42. What could be the identity of “A”? (8.04/8.05)

3. HCl                                        c. NH3
4. NaCl                                        d. KOH

43. Which of the following is the least basic (8.04/8.05)?

1. Acetic Acid (Vinegar); pH = 2.5        
2. Sodium bicarbonate Solution (Baking Soda); pH = 8.5
3. Kids mouthwash; pH = 5        
4. Hand soap; pH = 6

44. Which of the following best describes the picture below? (8.05)

5. It is a strong acid because all the particles dissociated in solution
6. It is a weak acid because all the particles dissociated in solution
7. It is a strong acid because some of the particles dissociated in solution
8. It is a weak acid because some of the particles dissociated in solution

The following may help for question #45:

Logarithm Review (from lesson)           Antilog Review (from lesson)

pH = −log⁡[ H3O+ ]                pOH = −log[ OH− ]                

⁡[ H3O+ ] = 10−pH                  [ OH− ]= 10−pOH

pH + pOH = 14                      [ H3O+ ] × [ OH− ] = 1.0 × 10−14 M

45. What is the hydroxide concentration of a solution that is pH = 3.7? (8.05)

1. 0.56 M                                c. 1.99 X 10-4 M
2. 5.03 X 10-11 M                        d. 0.482 M

Honors Multiple Choice:

46. (5.03H) Which of the following does NOT share the same empirical formula?

1. H2O and H2O2                        c.  C4H16 and C2H8
2. C3H6O3 and C2H4O2                d.  CH2 and C10H20
   

47. (5.03H) A compound of iron and oxygen is analyzed and found to contain  69.94%  iron and  30.06%  oxygen. Find the empirical formula of the compound.

1. Fe4O6.                                c.  Fe1O1.5
2. FeO                                d.  Fe2O3

48. (6.06H) What is the volume of 4.50 moles of oxygen gas (O2) at standard temperature and pressure (STP)?

1. 101 L O2                        c.  202 L O2        
2. 50.5 L O2                        d. 150 L O2        .

49. (6.06H) If 52.0 g of magnesium metal reacts with excess hydrochloric acid, how many liters of hydrogen gas can be produced at 285K and 0.97 atm?

Mg (s) + 2HCl (aq)   → H2(g) + MgCl2 (aq)

3. 1254 L H2                        c.  123 L H2
4. 51.6 L H2                        d.  74.5 L H2

50. (6.06H) What assumption do we make when considering all gasses ideal?

1. We assume there are no attractive forces (intermolecular forces) between gas molecules
2. We assume that all gas molecules have the same volume
3. We assume that all gas molecules move in a consistent pattern
4. We assume there is pressure between gas molecules

51. (7.03H) What happens to the entropy in the reaction below?

 CO2 (g) + CaO (s)  → CaCO3 (s)

5. Increases                        c. Decreases
6. No change                        d. Not enough information

52. (7.03H)  Hot water is poured into the same amount of cold water in a calorimeter.  Which of the following statements is correct?

1. Both the cold water and hot water lose heat; neither gains it.
2. The energy change is the same for both substances.
3. The cold water and hot water experience a net loss of energy.
4. Both the cold water and hot water gain heat; neither loses it.

53. (7.03H) Which of the following formulas can be used to calculate the final temperature of a system in a calorimeter?

1. Tf = (q)(-Ti)                        c. Tf =      q              +   Ti                

        (m)(c)                                     (m)(c)

2. Tf = (q)(m)                         d. Tf = (q)(m)(c) - Ti

       (c)(-Ti)                                    

54. (7.06H) Under what pressure and temperature conditions can we shift the equilibrium to the right for the reaction below?

2A + B ↔  C + D     ΔH= −151kJ

3. High pressure, low temperature                
4. Pressure will have no effect, low temperature
5. Low pressure, high temperature                
6. Pressure will have no effect, high temperature

55. (7.06H) What will happen to the equilibrium when more 2SO2 (g) is added to the following system?

2SO2 (g) + O2 (g) ⇌ 2SO3 (g)

7. The equilibrium shifts to the right.                c. The equilibrium shifts to the left
8. The equilibrium does not change                d. Not enough information

56. (8.06H) What is the resource that best matches the following description: Heat energy from steam surfaces from circulating groundwater, moving turbines and creating electrical energy.

1. Geothermal energy                        c. Solar energy
2. Hydropower                                d.  Wind power

57. (8.06H)  Which resource is not a clean energy source, releases greenhouse gasses, but is good for protecting habitats?

1. Nuclear energy                        c.  Biomass energy
2. Geothermal energy                        d.  Coal