CHEM 100 FINAL REVIEW

We're Gonna Need a Bigger Calculator

100

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

A.  128 g/mol

B.  3.49 X 10²⁵ g/mol 

C.  2.13 X 10²² g/mol 

D.  4.70 X 10²¹ g/mol

E.  58.0 g/mol   

(Question #13 on Review Packet)

A.  128 g/mol

200

Methyl butyrate is a compound that is partically 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.  C_4.9H_9.8O_1.9

E.  C₄H₉O₂

(Question #16 on Review Packet)

B.  C₅H₁₀O₂

300

Phosphine, PH₃, a reactive and poisonous compound, reacts with oxygen as follows:

4PH₃(g) + 8O₂(g) —> P₄O₁₀(s) + 6H₂O(g)

If 15.0 g of phosphine reacts with sufficient oxygen, how many grams of P₄O₁₀ will be formed?

A.  125 g

B.  31.3 g

C.  5.00 X 10² g

D.  18.9 g

E.  75.7 g

(Question #22 on Review Packet)

B.  31.3 g

400

When a 0.525 g piece of zinc is placed in a solution of copper(II) sulfate, copper metal and zinc sulfate are formed.  Balance the equation for the reaction, and determine the mass of copper(II) sulfate that would react with this quantity of zinc.

__Zn(s) + CuSO₄(aq) —> ZnSO₄(aq) + Cu(s)

A.  65.4 g

B.  0.641 g

C.  1.28 g

D.  2.56 g

E.  159 g

(Question #23 on Review Packet)

C.  1.28 g

500

Aluminium metal reacts with sulfuric acid according to the equation:

2Al(s) +3H₂SO₄(aq) —> Al₂(SO₄)₃(s) + 3H₂(g) 

If 10.0 g of aluminum reacts with excess sulfuric acid, and 54.2 g of Al₂(SO₄)₃ are collected, what is the percent yield for the reaction?

A.  63.4%

B.  85.5%

C.  117%

D.  47.1%

E.  not enough information given

(Question #27 on Review Packet)

B.  85.5%

If It Were Easy, Everyone Would Do It

100

The correctly drawn Lewis formula for CBr₄ will have _______.

A.  4 single bonds

B.  5 single bonds  

C.  4 single bonds and 1 pair of nonbonding electrons on the carbon atom

D.  4 single bonds and 2 pairs of nonbonding electrons on the carbon atom

E.  4 single bonds and 3 pairs of nonbonding electrons on the carbon atom

(Question #32 on Review Packet)

A.  4 single bonds

200

Boron has two isotopes:  B-10 and B-11, with masses of 10.013 amu and 11.009 amu, respectively.  The relative atomic mass of boron is 10.81.  Which statement best describes the percent abundance of the isotopes of boron?

A.  It contains more B-10 than B-11.

B.  It contains more B-11 than B-10.  

C.  It contains equal amounts of B-10 than B-11.

D.  There must be a third isotope of boron.

E.  A mass spectrum of boron is necessary to answer this question.  

(Question #8 on Review Packet)

B.  It contains more B-11 than B-10.  

300

After the following equation is properly balanced, what is the coefficient in front of O₂(g)?

A.  1

B.  2

C.  3

D.  4

E.  6

(Question #19 on Review Packet)

C.  3

400

Based on the solubility rules, which of these processes will occur if solutions of CuSO₄(aq) and BaCl₂(aq) are mixed?

A.  CuCl₂ will precipitate;  Ba²⁺ and SO₄^2- are spectator ions.

B.  CuSO₄ will precipitate;  Ba²⁺ and Cl^- are spectator ions.

C.  BaSO₄ will precipitate;  Cu²⁺ and Cl^- are spectator ions.

D.  BaCl₂ will precipitate;  Cu²⁺ and SO₄^2- are spectator ions.

E.  No precipitate will form.

(Question #37 on Review Packet)

C.  BaSO₄ will precipitate;  Cu²⁺ and Cl^- are spectator ions.

500

Which of the following has a parent structure that is trigonal planar?

A.  NH₃ 

B.  H₂O

C.  SO₂

D.  CO₂ 

E.  all of these

(Question #33 on Review Packet)

C.  SO₂

Calculator or Not to Calculator

100

The proprietor of a rock shop insists that a nuggest is pure gold.  If the nugget occupies a volume of 5.40 mL, what would its mass have to be if it were truly pure gold? 

(d_gold = 19.3 g/mL)

A.  104 g

B.  3.57 g

C.  0.279 g

D.  13.9 g

E.  insufficient information given

(Question #1 on Review Packet)

A.  104 g

200

Which of the following substances can participate in hydrogen bonding?

A.  CH₄ 

B.  CHCl₃

C.  H₂S

D.  NH₃

E.  both H₂S and NH₃ 

(Question #40 on Review Packet)

D.  NH₃

300

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

A.  2.00 X 10³ moles 

B.  0.200 mole  

C.  0.294 mole 

D.  1.36 X 10³ moles   

E.  1.20 X 10³ moles   

(Question #14 on Review Packet)

B.  0.200 mole

400

How many formula units are in 0.25 mole of Na₂O?

A.  4.5 X 10²³ 

B.  0.75  

C.  1.5 X 10²³ 

D.  4.2 X 10^-25 

E.  0.25    

(Question #12 on Review Packet)

C.  1.5 X 10²³

500

What mass of NaCl is present in 125.0 mL of a 0.100 M NaCl solution?

A.  125 g

B.  12.5 g

C.  73.1 g

D.  0.731 g

E.  46.8 g

(Question #17 on Review Packet)

D.  0.731 g

You Have Chosen Wisely

100

The number of protons and neutrons in an atom of bromine-81 is:

A.  81 protons and 35 neutrons

B.  35 protons and 81 neutrons

C.  46 protons and 35 neutrons

D.  35 protons and 46 neutrons

(Question #7 on Review Packet)

D.  35 protons and 46 neutrons

200

Phosphorus trichloride can be made by the reaction:

P₄(s) + 6Cl₂(g) —> 4PCl₃(l) 

What is the maximum amound of phosphorous chloride that can be formed if 10 molecules of P₄ react with 36 molecules of chlorine?

A.  4 molecules

B.  6 molecules

C.  12 molecules

D.  24 molecules

E.  46 molecules

(Question #25 on Review Packet)

D.  24 molecules

300

If the theorectical yield for a reaction is 54.9 g, and 51.3 g are actually obtained, the percent yield is:

A.  0.934%

B.  93.4%

C.  107%

D.  3.60%

E.  not enough information given

(Question #26 on Review Packet)

B.  93.4%

400

If a child's balloon filled with helium were heated with a blow-dryer, the balloon would increase in volume.  What would happen to the density of the helium in the balloon?

A.  It would decrease.

B.  It would increase.

C.  It would remain the same.

D.  A chemical reaction would occur, so it is impossible to predict.

E.  The initial statement is incorrect- the volume of the balloon would not increase. 

(Question #2 on Review Packet)

A.  It would decrease.

500

Identify the net ionic equation for the following reaction:

2NaCl(aq) + Hg₂(NO₃)₂(aq) —> 2NaNO₃(aq) + Hg₂Cl₂(s)

A.  Na⁺(aq) + NO₃^- (aq) —> NaNO₃(aq)

B.  Hg₂²⁺(aq) + 2Cl^- (aq) —> Hg₂Cl₂(s)

C.  2Hg₂⁺(aq) + 2Cl^- (aq) —> 2HgCl(s)

D.  Hg₂(NO₃)₂(aq) —> 2Hg₂⁺(aq) + 2NO₃^- (aq)

E.  Hg₂²⁺(aq) —> Hg₂(s)

(Question #38 on Review Packet)

B.  Hg₂²⁺(aq) + 2Cl^- (aq) —> Hg₂Cl₂(s)

Hakuna Matata

100

Based on solubility rules, which one of these compounds is insoluble in water?

A.  NaCl

B.  MgBr₂

C.  FeCl₂

D.  AgBr

E.  ZnCl₂

(Question #35 on Review Packet)

D.  AgBr

200

What of the following is the correct ground state electron configuration for chlorine?

A.  1s²2s²2p⁵

B.  1s²2s²2p⁶3s²4p⁵

C.  1s²2s²2p⁶3s²3p⁵

D.  1s²2s²2p⁶3s²3p⁶

E.  1s²2s²2p⁶3s²4p⁶

(Question #28 on Review Packet)

C.  1s²2s²2p⁶3s²3p⁵

300

[See Picture Prompt]

(Question #20 on Review Packet)

Answer:  D

400

Consider the following reaction:

CrCl₃(s) + KCl(s) + 2H₂SO₄(l) —> KCr(SO₄)₂(s) +4HCl(g)

green       white     colorless        purple       colorless

A.  CrCl₃

B.  KCl

C.  H₂SO₄

D.  KCr(SO₄)₂

E.  HCl

(Question #24 on Review Packet)

A.  CrCl₃

500

Which set of formulas is correct for the compounds calcium hydrogen carbonate, magnesium chloride, and calcium sulfate, which can cause scale build-up in pipes?

A.  CaHCO₃, MgCl₂, and Ca(SO₄)₂

B.  CaHCO₃, MgCl, and Ca(SO₄)₂

C.  Ca(HCO₃)₂, MgCl, and CaSO₄

D.  Ca(HCO₃)₂, MgCl₂, and CaSO₄

E.  Ca(HCO₃)₂, MgCl₂, and Ca₂SO₄

(Question #10 on Review Packet)

D.  Ca(HCO₃)₂, MgCl₂, and CaSO₄