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 36.9

C 3.96

D 39.6

Question #2

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

A lose 3

B gain 3

C lose 1

D gain 1

Question #3

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

A The NaCl will fail to dissociate

B The solution will conduct electricity

C The solution will taste salty

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 4.7

B 44

C 4.6

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 5.4

B 45

C 4.5

D 54

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 1.6

C 2.6

D 6.1

Question #7

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

A MgS, AgI

B BaCO3, AgI

C MgSO4, KOH

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 color, physical state, number of moleclules, temperature

C mass, temperature, physical state, number of atoms

D mass, type of atoms, number of atoms, color

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 4

D 2

E 5

Question #10

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

A Na2SO4, NaCl, N2O6

B Na2SO4, NaCl, CO2

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

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

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

D Br-(aq) + Ag+(aq) →AgBr(s)

E NH4Br(aq) + AuC2H3O2(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 P2O3

D P3O5

E PO2

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 36

B 53

C 73

D 63

Question #14

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

A 41.8

B 48.9

C 45

D 4.81

E 48.1

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 2.37

B 21

C 134

D None of these responses apply.

E 237

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 1.9

B None of these responses apply.

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 2.99 x 1023

C 2.54 x 1023

D 5.15 x 1026

E 1.55 x 1023

Question #18

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

A S2Ba2

B AlN

C N3Al3

D Ba2S

E Al3N3

Question #19

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

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

A doubaby hexasharkite

B bibaby hexasharkide

C bibaby hexasharkade

D dibaby hexasharkide

Question #20

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

A maxite acid

B max acid

C maxim acid

D maxic acid

Question #21

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

A zinc nitrite

B zinc nitrade

C zinc nitrate

D zinc nitride

Question #22

Give the systematic name for the following substance:
Cs2Cr2O7

A cesium dichromide

B cesium dichromite

C cesium dichromate

D cesium chromate

Question #23

Give the systematic name for the following substance:
SF3

A sulfur trifluoride

B sulfur fluoride

C sulfur fluorite

D sulfur trifite

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 (II) pinkade

B iron (III) pinkade

C iron pink

D iron (III) pinkide

Question #25

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

A B2N3

B Ba3N2

C Ba2N3

D N2Ba3

E N3Ba2

F BaN

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