Exam 2

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Question #1

Consider the reaction CH4 + 2 O2 ⟶ CO2 + 2 H2O. It was determined that the maximum yield of CO2 is 5.66 g. However, when the experiment was carried out only 2.24 g of CO2 was recovered. What is the percent yield of CO2.

A 396

B 3.96

C 36.9

D 39.6

Question #2

How many electrons will chlorine gain or lose when it forms an ion?

A lose 3

B gain 1

C gain 3

D lose 1

Question #3

When solid NaCl is stirred into water, which of the following is NOT true?

A The solution will taste salty

B The NaCl will fail to dissociate

C The solution will conduct electricity

D Individual sodium and chloride ions are present

Question #4

Find the mass in grams of chlorine that are in 4.8 g of CCl4? give answer as decimal notation; do not include units.

A 44

B 4.6

C 4.7

D 4.4

Question #5

Consider the equation 2 C3H6 + 9 O2 ⟶ 6 CO2 +6 H2O. How many moles of CO2 are produced if 5.3 moles of C3H6 reacts with 6.8 moles of O2. Do not include units.

A 45

B 5.4

C 54

D 4.5

Question #6

Consider the reaction 2 Al(s) + 6 HCl(aq) ⟶ 2 AlCl3(aq) + 3H2(g)
An excess amount of Al is added to 58 g HCl. What is the theoretical yield (in grams) of H2? Do not include units.

A 1.9

B 2.6

C 6.1

D 1.6

Question #7

Which of the following compounds is/are soluble in water?

A BaCO3, AgI

B MgSO4, KOH

C MgS, AgI

D BaCO3, MgS

Question #8

Which of the following may change in a chemical reaction and does not always stay constant?

A mass, type of atoms, physical state, number of atoms

B mass, type of atoms, number of atoms, color

C color, physical state, number of moleclules, temperature

D mass, temperature, physical state, number of atoms

Question #9

When the following equation is balanced what is the coefficient of H2O(g)? Give your answer as a number.
C2H6(s) + O2(g) ⟶ H2O(g) + CO2(g)

A 3

B 6

C 2

D 4

E 5

Question #10

Which of the following are empirical formulas but not molecular formulas?

A Na2SO4, NaCl, CO2

B Na2SO4, NaCl, N2O6

C Na2SO4, N2O6, CO2

Question #11

What is the net ionic equation for the reaction that occurs when ammonium bromide is reacted with silver acetate?

A NH4+(aq) + C2H3O2-(aq) → NH4C2H3O2(aq)

B NH4Br(aq) + AuC2H3O2(aq) →(s) + NH4C2H3O2(aq)

C Br-(aq) + Ag+(aq) →AgBr(s)

D NH3Br(aq) + AgC2H3O2(aq) →(s) + NH3C2H3O2(aq)

E NH4Br(aq) + AgC2H3O2(aq) →(s) + NH4C2H3O2(aq)

Question #12

A substance is analyzed and it is found to contain 0.392 moles of phosphorus atoms and 0.653 moles oxygen atoms. What is the empirical formula of this compound?

A PO3

B PO

C PO2

D P3O5

E P2O3

F P3O2

Question #13

You have 9 molecules of N2O5. How many atoms do you have? Give a numerical value. Do not include units.

A 53

B 63

C 36

D 73

Question #14

To 3 significant figures, what is the mass percent of sulfate in Pb(SO4)2? Do not include any units.

A 48.9

B 48.1

C 4.81

D 41.8

E 45

Question #15

The reaction for the oxidation of NH3 is given as:
4 NH3 + 5 O2 → 4 NO + 6 H2O

Under certain conditions the reaction will proceed at 29.8% yield of NO. How many grams of NH3 must be used to react with excess oxygen to yield 70.5 g of NO? Hint: 70.5 g of NO is the actual yield.

A 21

B 134

C 2.37

D 237

E None of these responses apply.

Question #16

If a sample of carbon dioxide contains 3.8 moles of oxygen atoms, how many moles of carbon dioxide are in the sample?

A None of these responses apply.

B 1.9

C 3.8

D 7.6

E 11.4

Question #17

How many molecules of ethanol (C2H5OH) are contained in 15.0 mL of ethanol? The density of ethanol is 0.789 g/mL.

A None of these responses apply.

B 1.55 x 1023

C 2.99 x 1023

D 5.15 x 1026

E 2.54 x 1023

Question #18

Write the chemical formula for the compound that forms between aluminum and nitride

A S2Ba2

B Ba2S

C Al3N3

D AlN

E N3Al3

Question #19

Use the systematic rule to name the following hypothetical compound:
Bb2Sh6

Note: Bb = baby, Sh = shark. Bb and Sh are nonmetals.

A dibaby hexasharkide

B bibaby hexasharkade

C doubaby hexasharkite

D bibaby hexasharkide

Question #20

An hypothetical polyatomic ion MxO2- is named maxite.
Use the systematic rules to name the following hypothetical compound: HMxO3

A maxic acid

B maxite acid

C maxim acid

D max acid

Question #21

Give the systematic name for the following substance:
Zn(NO2)2

A zinc nitrade

B zinc nitride

C zinc nitrate

D zinc nitrite

Question #22

Give the systematic name for the following substance:
Cs2Cr2O7

A cesium dichromate

B cesium dichromite

C cesium dichromide

D cesium chromate

Question #23

Give the systematic name for the following substance:
SF3

A sulfur trifluoride

B sulfur trifite

C sulfur fluorite

D sulfur fluoride

Question #24

Name the following substance:
Fe2Pk3 where Pk is a hypothetical element named “Pink”. The ion form of Pink is a -2 charge.

A iron pink

B iron (III) pinkide

C iron (II) pinkade

D iron (III) pinkade

Question #25

Which of the following is the correct formula that forms between nitrogen and barium?

A Ba3N2

B BaN

C Ba2N3

D B2N3

E N2Ba3

F N3Ba2

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