SparkNotes: Review of Stoichiometry: Review Test

1. Which of the following are chemically engineered products?

(A) Glue

(B) Tires

(C) Aspirin

(D) All of the above

2. A mole is a measure of:

(A) Amount of substance

(B) Weight of substance

(C) Mass of substance

(D) 6.02×10²³

3. True or False: Only at STP will 1 mole of substance contain 6.02×10²³ particles.

(A) True

(B) False

4. How many inches are there in 18 yards?

(A) 54

(B) 648

(C) 216

(D) 12

5. How many atoms are there in 3 moles of H₂O?

(A) 3

(B) 6.02×10²³

(C) 1.806×10²⁴

(D) 5.418×10²⁴

6. A mole ratio is:

(A) A fraction

(B) A ratio

(C) A conversion factor

(D) All of the above

7. Given the following balanced equation: N₂ +3H₂→2NH₃ Which of these is an INCORRECT mole ratio?

(A)

(B)

(C)

(D)

8. 4NH₃(g) + 6NO(g)→5N₂(g) + 6H₂O(g) How many moles of each reactant were there if 13.7 moles of N₂(g) is produced?

(A) 10.96 moles NH₃(g) and 16.44 moles NO(g)

(B) 2.74 moles NH₃(g) and 16.44 moles NO(g)

(C) 3.43 moles NH₃(g) and 5.15 moles NO(g)

(D) 54.8 moles NH₃(g) and 82.2 moles NO(g)

9. NaCl, Cl₂, C₂H₆O₂: Which has the greatest GFM?

(A) NaCl

(B) Cl₂

(C) C₂H₆O₂

(D) All have equal GFM

10. What is the GFM of Ca₃(PO₄)₂?

(A) 215 grams

(B) 215 grams/mole

(C) 310 grams

(D) 310 grams/mole

11. What is the mass of 2 moles of H₂S?

(A) 34 amu

(B) 34 grams

(C) 68 amu

(D) 68 grams

12. What does STP stand for and what are its conditions?

(A) Standard Temperature and Pressure, 0 degrees Celsius, 0 atm

(B) Standard Temperature and Pressure, 0 degrees Celsius, 1 atm

(C) Standard Temperature and Pressure, 25 degrees Celsius, 1 atm

(D) Stone Temple Pilots, condition: totally awesome

13. If I have 1 mole of H₂O, how many L is that?

(A) 22.4 L

(B) 44.8 L

(C) 67.2 L

(D) Not enough information given

14. What is the first step in solving a problem in stoichiometry?

(A) Balance the equation

(B) Convert to moles

(C) Mole ratio

(D) Convert to desired untis

15. Ammonium nitrate decomposes according to the following equation: NH₄NO₃→N₂ + H₂O + O₂ Given that you start with 8 moles of NH₄NO₃, how much O₂ will be produced? (Assume ideal conditions)

(A) 8 moles

(B) 22.4 Liters

(C) 128 grams

(D) 256 grams

16. 2Al +3Cl₂→2AlCl₃ When 0.8 kg grams of aluminum is reacted with excess chlorine gas, how many formula units of AlCl₃ are produced?

(A) 1.78×10²²

(B) 1.78×10²³

(C) 1.78×10²⁵

(D) 3.57×10²⁵

17. Sb₂S₃(s) + 3Fe(s)→2Sb(s) + 3FeS(s) If 3.87×10²³ particles of Sb₂S₃(s) are reacted with excess Fe(s), what mass of FeS(s) is produced?

(A) 157 grams

(B) 170 grams

(C) 343 grams

(D) 314 grams

18. CO(g) +2H₂(g)→CH₃OH(g) At STP, what volume of H₂(g) is needed to react completely with 8.02×10²³ molecules of CO(g)?

(A) 119.4 mL

(B) 29.8 L

(C) 59.7 L

(D) 119.4 L

19. 4Al +4O₂→2Al₂O₃ 13.2 moles of Al reacts completely with excess O₂, how much 2Al₂O₃ is produced?

(A) 26.4 moles

(B) 73.92 L

(C) 3.973×10²⁴ particles

(D) 283.8 grams

20. SiO₂(s) + 3C(s)→SiC(s) + 2CO(g) At STP, how many kg of SiO₂(s) reacted if 680 mL of CO(g) were produced?

(A) 6.68×10^-4

(B) 0.668

(C) 1.336

(D) 668

21. At STP, which is equivalent to 1 mole?

(A) 6.02×10²³ particles

(B) 22.4 L

(C) GFM

(D) All of the above

22. I combine 75 L of hydrogen gas with excess iodine at STP. The resulting reaction is as follows: H₂ + I₂→2HI How many HI particles are produced?

(A) 6.02×10²³

(B) 2.016×10²⁴

(C) 4.03125×10²⁴

(D) 8.0625×10²⁴

23. You have 4 moles O₂ and 2 moles of FeS₂ and are given the following balanced equation: 4FeS₂ + 11O₂→2Fe₂O₃ +8SO₂ Which reactant is the limiting reagent?

(A) FeS₂

(B) O₂

(C) Fe₂O₃

(D) SO₂

24. Li₃N(s) +3H₂O(l)→NH₃(g) + 3LiOH(aq) How many mL of NH₃(g) are produced at STP when 7.88×10²⁴ molecules of water reacts with 120 grams of Li₃N(s)?

(A) 25.6

(B) 76.8

(C) 97.7

(D) 76,800

25. The following equation is balanced: CaCO₃ +2HCl→CaCl₂ + CO₂ + H₂O Density is measured in grams/Liter. 345 grams of CaCO₃ reacts with excess HCl to produce 200 L of CO₂. What is the density of the CO₂?

(A) 0.71 grams/Liter

(B) 0.76 grams/Liter

(C) 1.12 grams/Liter

(D) 760 grams/Liter

26. CaCO₃(s) + 176 kJ→CaO(s) + CO₂(g) What is the percent yield if 49.6 g of CaCO₃(s) produces 13.1 grams of CaO?

(A) 2.28 %

(B) 26.4 %

(C) 47.1 %

(D) 228 %

27. True or False: A percent yield of 90 % - 100 % is common in chemistry.

(A) True

(B) False

28. 2Zn + O₂→2ZnO What is the percent yield of this reaction if 14 moles of ZnO are produced from the reaction of 256 grams of O₂ with excess Zn?

(A) 42.9 %

(B) 57.1 %

(C) 87.5 %

(D) None of the above

29. 2KClO₃(s)→2KCl(s) + 3O₂(g) If the percent yield is 40%, how many atoms of O are produced from 6.02×10²³ formula units of KClO₃(s)?

(A) 9.03×10²³

(B) 1.806×10²³

(C) 1.806×10²⁴

(D) 3.612×10²⁴

30. 2KClO₃(s)→2KCl(s) + 3O₂(g) At STP, 9.83×10²⁴ formula units of KClO₃(s) decompose into KCl and 82 L of O₂(g). What is the percent yield?

(A) 7.47 %

(B) 14.9 %

(C) 44.7 %

(D) 89.5 %

31. The amount of heat a substance has at a given temperature and pressure is known as:

(A) Enthalpy

(B) Heat of reaction

(C) Heat of formation

(D) Core temperature

32. C(s) + O₂(g)→CO₂(g) + 393.5 kJ What kind of reaction is this?

(A) Exothermic

(B) Endothermic

(C) Neither

(D) Both

33. N₂(g) + O₂(g) + 43.2 kcal→2NO(g) What kind of reaction is this?

(A) Exothermic

(B) Endothermic

(C) Neither

(D) Both

34. What is the atomic mass of magnesium-26?

(A) 24 amu

(B) 26 amu

(C) 24 grams/mole

(D) 26 grams/mole

35. 2Mg(s) + O₂→2MgO(s) + 288 kcal How much heat is given off when 8.5 grams of magnesium-26 reacts with excess \ O₂?

(A) 47.1 kJ

(B) 196.8 kcal

(C) 196.8 kJ

(D) 393.6 kJ

36. CaCO₃(s) + 176 kJ→CaO(s) + CO₂(g) How much energy is required to decompose 10.4 moles of CaCO₃(s)?

(A) 176 kJ

(B) 915 kJ

(C) 1830 kJ

(D) None of the above

37. 2CO₂(g) + 43.9 kJ→2CO(g) + O₂(g) How many molecules of 2CO₂(g) can be decomposed by the addition of 20 kcal of heat energy?

(A) 2.73×10²³

(B) 5.47×10²³

(C) 1.146×10²⁴

(D) 2.293×10²⁴

38. SO₃(g) + H₂O(l)→H₂SO₄(aq) + 129.6 kJ At STP, if 540 kJ is released, what volume of SO₃(g) was originally added?

(A) 24.1 mL

(B) 24.1 L

(C) 93.3 L

(D) 1.57×10⁶ L

39. True or False: The state (s,l,g,aq) of all reactants and products MUST be given in an enthalpy reaction.

(A) True

(B) False

40. 2Cl(g)→C₂ What is the standard heat of formation for the reaction?

(A) H_f = 0

(B) Impossible to find since it is impossible to directly measure the absolute enthalpy of a substance

(C) Impossible to find since not enough information is given

41. Which is the correct equation for heat of reaction?

(A) δH = δH(products) - δH(reactants)

(B) δH = δH(reactants) - δH(products)

(C) δH = δH_f(products) - δH_f(reactants)

(D) δH = δH_f(reactants) - δH_f(products)

42. 2NO₂(g)→2NO(g) + O₂ Calculate the change in enthalpy for this equation given the following two heats of formation:

δH_fNO₂(g) = 33.85 kJ / mole

δH_fNO(g) = 90.37 kJ / mole

(A) 113.04 kJ

(B) 56.52 kJ

(C) -113.04 kJ

(D) -56.52 kJ

43. 2SO₂(g) + O₂(g)→2SO₃(g) Find the heat of reaction for this equation given the following two heats of formation:

δH_fSO₂ = -296.8 kJ / mole

δH_fSO₃ = -395.7 kJ / mole

(A) 141.97 kcal

(B) -23.7 kcal

(C) -141.97 kcal

(D) -593.4 kcal

44. 2SO₂(g) + O₂(g)→2SO₃(g) Find the heat of reaction for this equation given you have 4.5 moles of SO₂(g), excess oxygen, and the following two heats of formation:

δH_fSO₂ = -296.8 kJ / mole

δH_fSO₃ = -395.7 kJ / mole

(A) -319.4 kcal

(B) 319.4 kcal

(C) -141.97 kcal

(D) -63.1 kcal

45. I had 1 mole of NaCl and I put it in 2 L of solution. Which of the following is FALSE?

(A) I have a 0.5 M solution of Na⁺

(B) I have a 0.5 M solution of Cl^-

(C) I added 58 g of NaCl to the solution

(D) I have 22.4 L of solution

46. 3CaCO₃(s) + 2H₃PO₄(aq)→Ca₃(PO₄)₂(aq) + 3CO₂(g) + 3H₂O(l) How much 3CaCO₃(s) was added if 650 mL of 2.5 M Ca₃(PO₄)₂(aq) was produced?

(A) 1.625 grams

(B) 4.875 grams

(C) 1.625 moles

(D) 4.875 moles

47. Can the normality of a solution be numerically equivalent to its molarity?

(A) Yes

(B) No

48. I have a 1 N solution of Ca(OH)₂ and a 1 M solution of NaCl. Which of the following are equivalent?

(A) Particles of OH^- and particles of Cl^-

(B) Grams of Ca(OH)₂ and grams of NaCl (before dissolving)

(C) Moles of Ca²⁺ and moles of Cl^-

(D) Not enough information is given

49. 2P₂O₅ +6H₂O→4H₃PO₄ After 0.32 moles of P₂O₅ is dropped in a beaker of water, 500 mL remains. What is the normality of the resulting solution?

(A) 0.00384 N

(B) 1.28 N

(C) 3.84 N

(D) 7.69 N

50. 2Na₂O₂(s) + 2H₂O(l)→O₂(g) + 4NaOH(aq) After 27.6 grams of Na₂O₂(s) is dropped into a beaker of water, 80 mL remains. What is the normality of the resulting solution?

(A) 0.0044 N

(B) 0.0089 N

(C) 4.4 N

(D) 8.8 N

Review of Chemical Bonding

Review Test