The compound ba no3 2 includes oxygen atoms

Directions:

1. SHOW ALL WORK in the space provided or your answer is VOID!

1. How many formula units are there in 2.5 moles of MgCl2?

A) 2.5 B) 7.5 C) 1.5  1024 D) 4.5  1024 E) 4.2  10–24

Show your work below or ZERO POINTS!

2. How many chloride ions are present in 0.100 mol of MgCl2?

A) 0.200 Cl– ions D) 3.32  10–25 Cl– ions

B) 6.02  1022 Cl– ions E) 3.01  1024 Cl– ions

C) 1.20  1023 Cl– ions

Show your work below or ZERO POINTS

3. How many nitrate ions are present in 0.200 mol of Zn(NO3)2?

A) 1.20  1023 NO3– ions D) 6.64  10–25 NO3– ions

B) 2.41  1023 NO3– ions E) 0.400 NO3– ions

C) 3.01  1024 NO3– ions

Show your work below or ZERO POINTS

4. Consider the following chemical equations. Select the equations that represent chemical reactions, rather than physical changes.

I. CH4(g) + O2(g)  CO2(g) + H2O(g)

II. C2H5OH(l)  C2H5OH(g)

III. NaOH(s)  Na+(aq) + OHˉ(aq)

A) I, II, and III D) II and III only

B) I and II only E) I only

C) I and III only

Show your work below or ZERO POINTS

5. Calculate the molar mass of CuSO4·5H2O.

A) 159.62 g/mol D) 185.72 g/mol

B) 249.70 g/mol E) 446.48 g/mol

C) 177.64 g/mol

Show your work below or ZERO POINTS

6. If 4.05  1023 molecules of a substance have a mass of 86.2 g, what is the molar mass of the substance?

A) 128 g/mol D) 4.70  1021 g/mol

B) 3.49  1025 g/mol E) 58.0 g/mol

C) 2.13  1022 g/mol

Show your work below or ZERO POINTS

7. Consider the following chemical equations. Select the equations that represent chemical reactions, rather than physical changes.

I. 2NO(g) + O2(g)  2NO2(g)

II. CO2(s)  CO2(g)

III. Pb(NO3)2(aq) + 2AgCl(aq)  PbCl2(s) + 2AgNO3(aq)

A) I, II, and III D) II and III only

B) I and II only E) I only

C) I and III only

Show your work below or ZERO POINTS

8. Write a complete, balanced equation for the reaction that occurs when sodium metal reacts with water to form hydrogen gas and aqueous sodium hydroxide.

A) Na(s) + H2O(l)  NaOH(aq) + H(g)

B) Na(s) + H2O(l)  NaOH(aq) + H2(g)

C) Na(s) + 2H2O(l)  NaOH(aq) + 2H2(g)

D) Na(s) + 2H2O(l)  2NaOH(aq) + 2H2(g)

E) 2Na(s) + 2H2O(l)  2NaOH(aq) + H2(g)

Show your work below or ZERO POINTS

9. Zinc metal will react with aqueous hydrochloric acid to produce aqueous zinc chloride and hydrogen gas. Write a complete, balanced equation for this reaction.

A) Zn(s) + HCl(aq)  ZnCl(aq) + H(g)

B) Zn(s) + HCl(aq)  ZnCl(aq) + H2(g)

C) Zn(s) + 2HCl(aq)  ZnCl(aq) + H2(g)

D) Zn(s) + 2HCl(aq)  ZnCl2(aq) + H2(g)

E) 2Zn(s) + 2HCl(aq)  2ZnCl(aq) + H2(g)

Show your work below or ZERO POINTS

10. Calculate the number of moles of NaHCO3 (sodium bicarbonate, or baking soda) in a 5.0 g sample of this substance.

A) 0.096 mole D) 3.6  1022 moles

B) 0.060 mole E) 2.8  1023 mole

C) 420 moles

Show your work below or ZERO POINTS

11. Calculate the number of moles of NaOH (sodium hydroxide, an ingredient in drain cleaners and oven cleaners) in a 10.0 g sample of this substance.

A) 1.51  1023 moles D) 4.00  102 moles

B) 1.66  1023 mole E) 0.250 mole

C) 0.208 mole

Show your work below or ZERO POINTS

12. Calculate the number of moles of CaCO3 (calcium carbonate, or limestone) in a 20.0 g sample of this substance.

A) 2.00  103 moles D) 1.36  103 moles

B) 0.200 mole E) 1.20  103 moles

C) 0.294 mole

Show your work below or ZERO POINTS

13. When solid ammonium carbonate is heated, it decomposes to form ammonia gas, carbon dioxide gas, and water vapor, so that the solid completely disappears. Write a complete, balanced equation for this reaction.

A) NH4CO3(s)  NH3(g) + CO2(g) + H2O(g)

B) NH4CO3(s)  NH2(g) + CO2(g) + H2O(g)

C) (NH4)2CO3(s)  NH3(g) + CO2(g) + H2O(g)

D) (NH4)2CO3(s)  NH3(g) + CO2(g) + 3H2O(g)

E) (NH4)2CO3(s)  2NH3(g) + CO2(g) + H2O(g)

Show your work below or ZERO POINTS

14. Balance the following skeletal equation: C2H5OH(l) + O2(g)  CO2(g) + H2O(g).

A) C2H5OH(l) + O2(g)  CO2(g) + 3H2O(g)

B) C2H5OH(l) + O2(g)  2CO2(g) + 3H2O(g)

C) C2H5OH(l) + 2O2(g)  2CO2(g) + 3H2O(g)

D) C2H5OH(l) + 3O2(g)  2CO2(g) + 3H2O(g)

E) 2C2H5OH(l) + 3O2(g)  4CO2(g) + 3H2O(g)

Show your work below or ZERO POINTS

15. Balance the following skeletal equation: NH3(g) + O2(g)  NO2(g) + H2O(g).

A) 4NH3(g) + 7O2(g)  4NO2(g) + 6H2O(g)

B) 2NH3(g) + 2O2(g)  2NO2(g) + 3H2O(g)

C) 2NH3(g) + O2(g)  NO2(g) + 2H2O(g)

D) NH3(g) + O2(g)  NO2(g) + 2H2O(g)

E) NH3(g) + O2(g)  NO2(g) + H2O(g)

Show your work below or ZERO POINTS

16. Balance the following skeletal equation:

Ba(NO3)2(aq) + K2SO4(aq)  BaSO4(s) + KNO3(aq)

A) Ba(NO3)2(aq) + K2SO4(aq)  BaSO4(s) + KNO3(aq)

B) 2Ba(NO3)2(aq) + K2SO4(aq)  2BaSO4(s) + KNO3(aq)

C) 2Ba(NO3)2(aq) + 2K2SO4(aq)  2BaSO4(s) + 2KNO3(aq)

D) 2Ba(NO3)2(aq) + 2K2SO4(aq)  2BaSO4(s) + 3KNO3(aq)

E) Ba(NO3)2(aq) + K2SO4(aq)  BaSO4(s) + 2KNO3(aq)

Show your work below or ZERO POINTS

17. After the following equation is properly balanced, what is the coefficient in front of O2?

S8(s) + O2(g)  SO3(g)

A) 2 B) 3 C) 8 D) 12 E) 16

Show your work below or ZERO POINTS

18. A reaction which has two elements as reactants and one compound as a product is:

A) a decomposition reaction. D) a double-displacement reaction.

B) a combination reaction. E) a combustion reaction.

C) a single-displacement reaction.

Show your work below or ZERO POINTS

19. A solution of silver nitrate is mixed with a solution of sodium chloride, resulting in a precipitate of silver chloride and a solution of sodium nitrate. The class of this reaction is:

A) decomposition reaction. D) double-displacement reaction.

B) combination reaction. E) combustion reaction.

C) single-displacement reaction.

Show your work below or ZERO POINTS

20. A piece of magnesium metal is placed in a solution of hydrochloric acid, resulting in the formation of hydrogen gas and a solution of magnesium chloride. The class of this reaction is:

A) decomposition reaction. D) double-displacement reaction.

B) combination reaction. E) combustion reaction.

C) single-displacement reaction.

Show your work below or ZERO POINTS

21. The class of the reaction shown in the figure is:

image1.png

A) decomposition reaction. D) double-displacement reaction.

B) combination reaction. E) combustion reaction.

C) single-displacement reaction.

Show your work below or ZERO POINTS

22. Write and balance the equation for the decomposition reaction that occurs when Mercury(II) oxide decomposes to its elements.

A) 2HgO(s)  2Hg(l) + O2(g) D) HgO2(s)  Hg(l) + 2O(g)

B) Hg2O(s)  2Hg(l) + O2(g) E) 2Hg(l) +O2(g)  HgO2(s)

C) HgO(s)  Hg(l) + O2(g)

Show your work below or ZERO POINTS

23. When writing a net ionic equation, how would Mg(NO3)2(aq) be represented?

A) Mg2+(aq) + 2NO3–(aq) D) Mg(aq) + N2(aq) + 3O2(aq)

B) Mg2+(aq) + NO3–(aq) E) Mg2+(aq) + 2N3–(aq) + 6O2–(aq)

C) Mg2+(aq) + (NO3)2–(aq)

Show your work below or ZERO POINTS

24. Write and balance a net ionic equation for the reaction between hydrochloric acid and potassium hydroxide.

A) HCl(aq) + KOH(aq)  KCl(aq) + H2O(l)

B) H+(aq) + O2ˉ(aq)  OHˉ(aq)

C) H+(aq) + OHˉ(aq)  H2O(l)

D) Clˉ(aq) + OH+(aq)  OHCl(aq)

E) K+(aq) + Clˉ(aq)  KCl(aq)

Show your work below or ZERO POINTS

25. Write and balance a net ionic equation for the reaction between iron(II) chloride and potassium hydroxide to form iron(II) hydroxide and potassium chloride.

A) Fe2Cl(aq) + OHˉ(aq)  FeOH(s) + Clˉ(aq)

B) Fe2+(aq) + OHˉ(aq)  FeOH(s)

C) Fe2+(aq) + 2OHˉ(aq)  Fe(OH)2(s)

D) 2Clˉ(aq) + 2K+(aq)  2KCl(s)

E) 2Clˉ(aq) + 2K+(aq)  2K(s) + Cl2(g)

Show your work below or ZERO POINTS

26. When potassium metal is placed in water, will a reaction occur? If so, what is the balanced equation for the reaction?

A) No reaction will occur.

B) Yes. 2K(s) + 2H2O(l)  2K(OH)2(aq) + H2(g)

C) Yes. 2K(s) + 2H2O(l)  2KOH(aq) + H2(g)

D) Yes. 2K(s) + 2H2O(l)  2KH2O(aq)

E) Yes. 2K(s) + 2H2O(l)  2KOH(aq) + 2H2(g)

Show your work below or ZERO POINTS

27. When iron metal is placed into a solution of hydrochloric acid, will a reaction occur? If so, what is the balanced equation for the reaction?

A) No reaction will occur.

B) Yes. 2Fe(s) + 2HCl(aq)  2FeCl(aq) + H2(g)

C) Yes. Fe(s) + 2HCl(aq)  FeCl2(aq) + H2(g)

D) Yes. Fe(s) + 3HCl(aq)  FeCl3(aq) + H2(g)

Show your work below or ZERO POINTS

28. When copper metal is placed in a solution of zinc nitrate, will a reaction occur? If so, what is the balanced equation for the reaction?

A) Yes. Cu(s) + Zn(NO3)2(aq)  CuNO3(aq) + ZnNO3(aq)

B) Yes. Cu(s) + Zn2NO3(aq)  CuNO3(aq) + Zn(aq)

C) Yes. Cu(s) + Zn(NO3)2(aq)  Cu(NO3)2(aq) + Zn(s)

D) No reaction will occur.

E) Yes. Cu(s) + Zn2NO3(aq)  CuNO3(aq) + 2Zn(aq)

Show your work below or ZERO POINTS

29. When heated, calcium carbonate (limestone) undergoes a decomposition reaction. Write a balanced equation for this reaction.

A) CaCO3(s)  Ca(s) + CO3(g) D) 2CaCO3(s)  2CaO(s) + CO2(g)

B) CaCO3(s)  Ca(s) + CO2(g) E) 2CaCO3(s)  2CaO(s) + 3CO2(g)

C) CaCO3(s)  CaO(s) + CO2(g)

Show your work below or ZERO POINTS

30. Which of the following ionic compounds would be expected to be insoluble in water?

A) KCl B) PbI2 C) NH4NO3 D) CuSO4 E) NaCH3CO2

Show your work below or ZERO POINTS

31. Which of the following ionic compounds would be expected to be insoluble in water?

A) CaS B) Ca(NO3)2 C) Na2SO4 D) KI E) NaOH

Show your work below or ZERO POINTS

32. A 5.05 g sample of quartz (SiO2) contains 2.36 g of silicon. What are the percents of silicon and oxygen in quartz?

A) 53.3% Si and 46.7% O

B) 46.7% Si and 53.3% O

C) 29.9% Si and 70.1% O

D) 70.1% Si and 29.9% O

E) 46.7% Si, and insufficient information to calculate % O

Show your work below or ZERO POINTS

33. A 6.25 g sample of magnetite (Fe3O4) contains 4.52 g of Fe. What are the percents of iron and oxygen in magnetite?

A) 28.6% Fe and 71.4% O D) 27.7% Fe and 72.3% O

B) 42.8% Fe and 57.2% O E) 57.2% Fe and 42.8% O

C) 72.3% Fe and 27.7% O

Show your work below or ZERO POINTS

34. A 7.50 g sample of pyrite (FeS2) contains 3.49 g of iron. What are the percents of iron and sulfur in pyrite (also known as “Fool's Gold” because of its golden color)?

A) 57.4% Fe and 42.6% S D) 46.5% Fe and 53.5% S

B) 66.7% Fe and 33.3% S E) 53.5% Fe and 46.5% S

C) 33.3% Fe and 66.7% S

Show your work below or ZERO POINTS

35. Malachite is a green colored mineral that is 57.5% copper. What mass of copper is present in a 250.0 g sample of malachite?

A) 63.6 g B) 127 g C) 435 g D) 36.5 g E) 144 g

Show your work below or ZERO POINTS

36. Barium sulfate is a compound used to assist in diagnosing medical problems through x-ray analysis and is 58.8% barium. What mass of barium is present in a 620 mg tablet of barium sulfate?

A) 81 mg B) 230 mg C) 360 mg D) 1100 mg E) 11 mg

Show your work below or ZERO POINTS

37. Which of the following statements is incorrect?

A) PH3 has 3 times as many hydrogen atoms as phosphorus atoms.

B) MgO has an equal number of magnesium ions and oxygen ions.

C) BaBr2 has half as many barium ions as bromide ions.

D) N2O5 has 2.5 times as many nitrogen atoms as oxygen atoms.

E) SF4 has 4 times as many fluorine atoms as sulfur atoms.

Show your work below or ZERO POINTS

38. Which of the following statements is incorrect?

A) CH4 has ¼ as many carbon atoms as hydrogen atoms.

B) H2O has twice as many oxygen atoms as hydrogen atoms.

C) SO3 has three times as many oxygen atoms as sulfur atoms.

D) P4O10 has 2.5 times as many oxygen atoms as phosphorus atoms.

E) SrF2 has twice as many fluoride ions as strontium ions.

Show your work below or ZERO POINTS

39. Which of the following statements is incorrect?

A) N2H4 has four times as many hydrogen atoms as nitrogen atoms.

B) SF4 has ¼ as many sulfur atoms as fluorine atoms.

C) SO2 has twice as many oxygen atoms as sulfur atoms.

D) Ca(NO3)2 has six times as many oxygen atoms as calcium ions.

E) H2SO4 has twice as many oxygen atoms as hydrogen atoms.

Show your work below or ZERO POINTS

40. How many moles are in a sample of ethylene glycol (commonly found in antifreeze), HOCH2CH2OH, that has a volume of 250.0 mL? The molar mass and density of ethylene glycol are 62.07 g/mol and 1.11 g/mL, respectively.

A) 4.47 mol D) 1.40  104 mol

B) 0.276 mol E) 1.72  104 mol

C) 3.63 mol

Show your work below or ZERO POINTS

41. How many oxygen atoms are in 75.0 g of SO3?

A) 225 atoms D) 1.69  1024 atoms

B) 0.937 atoms E) 4.52  1025 atoms

C) 5.64  1023 atoms

Show your work below or ZERO POINTS

42. What is the mass of 4.5  1023 molecules of SO2?

A) 2.9  1025 g B) 64 g C) 86 g D) 36 g E) 48 g

Show your work below or ZERO POINTS

43. What is the mass of 2.4  1023 molecules of NO2?

A) 75 g B) 18 g C) 1.2  102 g D) 1.1  1023 g E) 12 g

Show your work below or ZERO POINTS

44. Which of the following statements regarding empirical formulas, molecular formulas, and percent composition is correct?

A) The compounds NO2 and N2O4 have the same empirical formula.

B) The compounds NO2 and N2O4 have the same molecular formula.

C) The empirical formula of H2O2 is H2O.

D) The empirical formula of N2O5 is NO2.5.

E) The compounds PCl3 and PCl5 would have the same percent composition.

Show your work below or ZERO POINTS

45. Methyl butyrate is a compound that is partially responsible for the flavor of apples. It consists of 58.80% C, 9.87% H, and 31.33% O. What is the empirical formula of methyl butyrate?

A) C6H10O3 B) C5H10O2 C) CH2O D) C4.9H9.8O1.9 E) C4H9O2

Show your work below or ZERO POINTS

46. Acetaminophen is the active ingredient in Tylenol. It consists of 63.56% C, 6.00% H, 9.27% N, and 21.17% O. What is the empirical formula of acetaminophen?

A) C8H8NO2 B) C8H9NO2 C) C6HNO2 D) C5.3H5.9N0.7O1.3 E) C4H4NO

Show your work below or ZERO POINTS

47. Acetic acid has a molar mass of 60.05 g/mol and consists of 40.00% C, 6.714% H, and 53.29% O. What is the molecular formula of acetic acid?

A) C3.33H6.66O3.33 B) C3H6O3 C) CH2O D) C2H4O2 E) CH3O

Show your work below or ZERO POINTS

48. Butyric acid has a very unpleasant odor. It is present in some rotting foods, body odor and vomit. Butyric acid has a molar mass of 88.10 g/mol and consists of 54.53% C, 9.153% H, and 36.32% O. What is the molecular formula of butyric acid?

A) CH2O0.5 B) CH2O C) CH4O D) C2H4O E) C4H8O2

Show your work below or ZERO POINTS

49. Acetaminophen is the active ingredient in Tylenol. It consists of 63.56% C, 6.00% H, 9.27% N, and 21.17% O. What is the empirical formula of acetaminophen?

A) C8H8NO2 B) C8H9NO2 C) C6HNO2 D) C5.3H5.9N0.7O1.3 E) C4H4NO

Show your work below or ZERO POINTS

50. Which of the following statements regarding empirical and molecular formulas is correct?

A) Information on percent composition is all that is necessary to determine both an empirical and a molecular formula.

B) A compound with an empirical formula of CH2O and a molar mass of 90 g/mol would have a molecular formula of C3H6O3.

C) The compounds C2H4 and C3H6 have different empirical formulas.

D) The formula Ca2Cl4 is the correct empirical formula for calcium chloride.

E) The compound benzene has a molecular formula of C6H6, so its empirical formula would be C3H3.

Show your work below or ZERO POINT

PAGE

4