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CHEM 167
Exam I Review
February 8, 2018

1.Many explosives produce N2 upon detonation because _____ .

a.it has a very strong bond

b.it is a gas

c.it is a very stable molecule

d.N2 is at a lower energy state than is N in the original explosive

e.all of the above are true.

2.Which one of the following is a strong electrolyte?

a.Fe(NO3)3b. NH3c. CH3CO2H d. H2O e. C6H12O6

3.45.0 g of sodium hypochlorite NaOCl is added to enough water to make 750.0 mL of solution. What is the molarity of the solution? (Sodium hypochlorite is the active ingredient in household bleach.)

a.0.604 b. 0.806 c. 1.24 d. 1.66 e. 74.4

4.What mass of aluminum has the same volume as 10.0 g of lead? Density of aluminum: 2.70 g/cm3; density of lead: 11.3 g/cm3

a.0.419 g b. 1.82 g c. 1.24 g d. 2.39 g e. 3.14 g

5.What is a monomer?

a.A molecule consisting of atoms of the same element

b.A group of atoms that make up polymers

c.An ion consisting of a single atom

d.A lone unpaired electron

e.None of the above is correct.

6.Which of the following atoms would form a covalent bond?

a.magnesium & oxygen (Mg & O) b. potassium & chlorine (K & Cl)

c. copper & aluminum (Cu & Al) d. sulfur & sulfur (S & S)

e. all of the above form covalent bonds

7.How should the result of the following calculation be reported?

a.b.

c. d. N

e. none of the above

8.What is the molecular formula of the molecule shown to the right? This compound helps give popcorn its characteristic smell.

a.C6H4NO b. C7H4NO c. C7H7NO d. C7H8NO e. C7H12NO

O

9.The isotope has ___ protons, ___ electrons, and ___ neutrons.

a.64, 64, 0 b. 30, 30, 34 c. 30, 30, 35.38

d. 34, 34, 30 e. 64, 64, 64

10.The atomic mass of copper is 63.55 and there are only two isotopes with a mass of 62.93 amu and with a mass of 64.93 amu. Which isotope is most abundant?

a.b. c.

d.the isotopes are equally abundant

e.not enough information has been provided to answer this question.

11.Which one of the following is the correct balanced net ionic reaction equation for the reaction of MgCl2 and AgNO3 in water?

a.MgCl2(aq) + AgNO AgCl2(s) + MgNO3(aq)

b.Mg2+(aq) + 2 NO3– Mg(NO3)2(s)

c.Ag+(aq) + Cl– AgCl(s)

d.Ag+(aq) + 2 Cl– AgCl2(s)

e.Mg AgCl2(s) + Mg2+(aq) + NO3–(aq)

12.When the strong acid HCl(aq) reacts completely with the strong base NaOH(aq), the resultant solution ______.

a.is nonconductive of electricity b. tastes salty

c. is slightly basic d. contains a precipitate

e. has a slight putrid odor.

13.Which one of the following has the greatest mass?

a.1 mole of N2b. 1 million N2 molecules

c. 1 molecule of N2d. 1 mole of NH3

e. 2 moles of H2

14.The most magnetic naturally occurring mineral on Earth is 72.4% Fe and 27.6% oxygen by mass.

Determine its empirical formula. How many Fe atoms are in a single formula unit for the mineral?

a.1 b. 2 c. 3 d. 4 e. 5

15.What is the charge on a stable halogen ion?

a. +1 b. +2 c. +3 d. –1 e. –2

16.When the following chemical reaction equation is balanced using integers (whole numbers), the coefficient in front of CO is ___ .

_____ Fe2O3(s)+ _____ CO _____ CO2(g) + _____ Fe (s)

a.1 b. 2 c. 3 d. 4 e. 5

17.What is the mass of 0.34 moles of (NH4)2S in grams?

a.0.0050 b. 0.043 c. 5.0 d. 23 e.

18.What is the correct name of the compound formed from barium Ba and chlorine Cl?

a barium chloride b. barium dichloride

c. barium (II) chloride d. bariummonochloride

e. none of the above

19.What is the correct name for S2N2? This molecule is square and is a shock sensitive explosive.

a sulfur nitride b. disulfurdinitride

c. bisulfurbinitrided. sulfur (II) nitride

e. none of the above

20.The molecule BCl3 is a useful reactant in organic synthesis acting as an electron pair acceptor. Which one of the following would also be expected to behave as an electron pair acceptor? [Hint: look at the periodic table]

a.NH3b. NCl3c. B2H6d. B2O3e. AlCl3

Ion / radius
picometers
(10–12 m)
Li+ / 90
Be2+ / 59
F– / 119
O2– / 121

21.Consider the table of ions and their radii. Which ions would experience the greatest repulsive force when placed side by side (i.e. touching)?

a. Li+ Be2+b. Be2+ Be2+ c. Be2+ O2–

d. O2– O2–e. O2– F–

22.Which one of the following statements about an atom is false?

a.The nucleus contains the vast majority of the mass of the atom.

b.Electrons circle the nucleus in well-defined circular orbits.

c.The nucleus is very dense.

d.Neutrons and protons make up the nucleus.

e.The nucleus is very small relative to the volume of the atom.

23.A cube measures 0.23 m on each side (a = 0.23 m). What is the volume of the cube in liters? V = a3 for a cube.

a.0.0012 L b. 0.12 L c. 1.2 L d. 12 L e. 1.2 L

24.What volume in liters of 6.0 molar HCl is needed to make 5.0 L of 1.5 molar HCl?

a.0.050 L b. 0.80 L c. 1.3 L d. 5.0 L e. 20. L

25.The products of complete combustion of a hydrocarbon in oxygen is/are ______.

a.H2 b. H2O c. CO2

d. a & b e. b & c

26. Determine the mass of hydrogen gas produced from the following information:
NaBH₄ + H₂SO₄ → B₂H₆ + H₂ + Na₂SO₄

(100g) (100g)
% yield = 79%

a.3.3g b. 5.2g c. 17.6g d. 26.1g

27. 100.0g of pentane are burned in 32g of oxygen to produce carbon dioxide and water. Which is the limiting reagent, and what is the yield of CO₂?

a. oxygen, 10g b. pentane, 28g c. oxygen, 28g d. pentane, 10g