Deck 3: Chemical Compounds

Question 1

Combustion analysis is one way to determine the simplest formula of some compounds.

Answer 1

True

Question 2

The number of atoms in 10.0 g of CaCO₃ (100.0 g/mol)is:

A)18.1 × 10^{22 atoms}
B)30.1 × 10^{22 atoms}
C)6.02 × 10^{22 atoms}
D)12.1 × 10^{23 atoms}
E)12.1 × 10^{22 atoms}

Answer 2

30.1 × 10^{22 atoms}

Question 3

For an ionic compound,the term formula mass is more appropriate than the term molecular mass.

Answer 3

True

Question 4

A 10.0 g sample of bismuth tribromide,BiBr₃,contains:

A)5.37 × 10²² total number of ions
B)0.322 mol BiBr₃
C)3.14 × 10²² formula units BiBr₃
D)1.34 × 10²² bromide ions
E)4.020 × 10²² total number of ions

Question 5

Choose the INCORRECT statement.

A)A structural formula shows which atoms are bonded together and by what type of bond.
B)Formula mass is the mass of a formula unit.
C)Molecular mass is the mass of a molecular compound.
D)The molecular mass of hydrogen is 1.008 u.
E)The molecular formula is the same as,or a multiple of,the empirical formula.

Question 6

Which of the following contains the greatest number of atoms?

A)1 mole of S₈ molecules
B)2 moles of P₄ molecules
C)4 moles of chlorine molecules
D)8 moles of H atoms
E)3 moles of ozone,O₃

Question 7

How many hydrogen atoms are present in 2.84 moles of water?

A)3.42 × 10²⁴ H atoms
B)1.71 × 10²⁴ H atoms
C)4.24 × 10²³ H atoms
D)9.44 × 10²⁴ H atoms
E)3.42 × 10²³ H atoms

Question 8

Polyatomic ions end in -ate or -ite.

Question 9

Oxidation state is related to the number of protons involved in bonding.

Question 10

Hydrocarbons contain only carbon and hydrogen.

Question 11

Chemical nomenclature is a systematic way of assigning names to chemical compounds.

Question 12

A 200.0 g sample of pure MgCl₂ contains:

A)95.211 formula units MgCl₂
B)2.101 formula units MgCl₂
C)1.265 × 10²⁴ formula units MgCl₂
D)1.204 × 10²⁶ formula units MgCl₂
E)5.734 × 10²⁵ formula units MgCl₂

Question 13

The structural formula is the simplest formula.

Question 14

Choose the INCORRECT statement.

A)A molecule is a group of bonded atoms that exist as an entity.
B)Ionic compounds result from combinations of metals and nonmetals.
C)An anion is a positive ion.
D)The empirical formula is the simplest formula of the ratio of atoms.
E)The molecular formula is the listing of the atoms in an actual molecule.

Question 15

Organic chemistry refers to compounds of oxygen,and hydrogen.

Question 16

A mole of the substance water,H₂O,refers to:

A)12.0000 g H₂O
B)one H₂O molecule
C)6.02 × 10²³ g H₂O
D)6.02 × 10²³ H₂O molecules
E)6.02 × 10²³ atoms of H and O

Question 17

Which of the following could be an empirical formula?

A)C₉H₈O₄ (aspirin)
B)C₆H₈O₆ (vitamin C)
C)C₈H₁₀N₄O₂ (caffeine)
D)C₁₀H₁₄N₂ (nicotine)

Question 18

Aspartame,C₁₄H₁₈N₂O₅,a low-calorie sweetener,is about 200 times sweeter than sugar.How many molecules of aspartame are there in a one-gram packet of sweetener containing 36 mg aspartame?

A)2.0 × 10¹⁸ molecules of aspartame
B)4.0 × 10²⁰ molecules of aspartame
C)7.2 × 10²⁵ molecules of aspartame
D)1.4 × 10²² molecules of aspartame
E)7.4 × 10¹⁹ molecules of aspartame

Question 19

Only metals in binary compounds use prefixes such as di-,tri-,tetra-,etc.

Question 20

A molecule is a group of bonded atoms that exist as an entity.

Question 21

Choose the INCORRECT name formula combination.

A)CaH₂ calcium hydroxide
B)SiO₂ silicon dioxide
C)HClO hypochlorous acid
D)Cu₃(PO₄)₂ copper(II)phosphate
E)AlCl₃ aluminum chloride

Question 22

Choose the INCORRECT oxidation state.

A)Cl is +5 in HClO₃
B)C is +4 in CS₂
C)S is +6 in H₂SO₃
D)C is -2 in CH₃OH
E)Br is +3 in BrF₃

Question 23

Combustion analysis of a 22.0 mg sample of the painkiller morphine produced 13.2 mg of water.What is the percentage by mass of hydrogen in morphine?

A)6.71%
B)3.36%
C)13.4%
D)60.0%

Question 24

Choose the INCORRECT oxidation state.

A)C is 0 in H₂CO
B)S is +4 in H₂SO₃
C)C is +2 in HCOOH
D)Fe is +2 in Fe₂O₃
E)Mn is +7 in KMnO₄

Question 25

The name of which compound ends in -ite?

A)HIO₃
B)Na₂SO₃
C)H₂SO₃
D)Na₂CO₃
E)CaH₂

Question 26

In which compound does carbon have an oxidation state of zero?

A)C₂H₂
B)CH₂O
C)CH₃OH
D)Na₂CO₃
E)CO₂

Question 27

In the following group,the compound with the greatest percentage of oxygen by mass is:

A)ClO₂
B)Na₂CO₃
C)P₄O₆
D)SO₂
E)As₂O₃

Question 28

White phosphorus,P₄,spontaneously bursts into flame in oxygen.If 6.500 g of white phosphorus reacts with oxygen to form 11.54 g of a phosphorus oxide,what is the empirical formula of this oxide?

A)P₂O₃
B)PO₃
C)P₂O₆
D)P₄O₆

Question 29

Crystals from evaporation of urine analyze to 22.6% phosphorus.Which compound is probably present?

A)NaNH₄HPO₄
B)(NH₄)₃PO₄
C)Na₃PO₄
D)H₃PO₄
E)Ca₃(PO₄)₂

Question 30

Which of the following functional groups gives acidic properties to organic molecules?

A)-C(O)CH₃
B)-COOCH₃
C)-COOH
D)-C(O)H
E)-CH₂OH

Question 31

Choose the INCORRECT name formula combination.

A)Fe₂O₃ iron(III)oxide
B)H₂SO₃ sulfurous acid
C)NH₄ClO₃ ammonium chlorate
D)CaH₂ calcium hydride
E)SiO₂ silicon oxide

Question 32

Choose the INCORRECT name formula combination.

A)HNO₂ nitrous acid
B)Fe₂(SO₄)₃ iron(III)sulfite
C)LiCN lithium cyanide
D)Na₂CO₃ sodium carbonate
E)Ba(OH)₂ barium hydroxide

Question 33

Nitroglycerin,C₃H₅N₃O₃:

A)has equal amounts of C and N by mass
B)has less than 50% O by mass
C)has the same proportion of N to H atoms as does NH₃
D)has the same mass percent of C and N
E)has higher mass percent of H than O

Question 34

Which of the following is(are)isomer(s)of organic compound with formula C₅H₁₂O?

A)4
B)1 and 2
C)1 and 3
D)6
E)5 and 4

Question 35

The explosive,trinitrotoluene,TNT,C₆H₃N₃O₆,has the same proportion of:

A)N to H atoms as does NH₃
B)H to O atoms as does H₂O
C)N to O atoms as does NO₂
D)C to H atoms as does C₆H₆
E)C to O atoms as does CO₂

Question 36

Choose the INCORRECT name/formula combination.

A)NaClO sodium hypochlorite
B)NaClO₄ sodium chlorate
C)NaClO₂ sodium chlorite
D)Sr(IO₃)₂ strontium iodate
E)SCl₄ sulfur tetrachloride

Question 37

Hydrates are:

A)moisture sensitive hygroscopic inorganic salts
B)compounds in which each formula unit has one or more water molecules associated with it
C)readily soluble in water and release energy
D)organic compounds that contain oxygen together with usual carbon and hydrogen
E)concentrated solutions of salts in water

Question 38

In which compound does iodine have an oxidation state of +3?

A)HIO₃
B)IF₅
C)Ca(IO₂)₂
D)HI
E)I₂

Question 39

Choose the INCORRECT name formula combination.

A)Fe₂(SO₄)₃ iron(III)sulfate
B)HBrO₃ bromic acid
C)PCl₅ phosphorus chloride
D)SCl₄ sulfur tetrachloride
E)Sr(IO₃)₂ strontium iodate

Question 40

Which of the following are isomers?

A)CH₃CH(CH₂CH₃)CH₂CH₂CH₃ and CH₃CH(CH₃)CH₂CH₂CH₃
B)CH₃CH(OH)CH₂CH₂CH₃ and CH₃CH(CH₃)CH₂CH₂CH₃
C)CH₃CH(OH)CH₂CH₂CH₃ and CH₃CH(OH)CH₂CH(CH₃)CH₃
D)CH₃CH(OH)CH₂CH₂CH₃ and CH₃CH(CH₃)CH₂CH₂OH
E)CH₃CH(CH₃)CH₂CH(CH₃)CH₃ and CH₃CH₂CH₂CH₂CH₃

Question 41

A 2.000 g sample of water contains 11.19% H by mass and 88.81% O by mass.What percent of H by mass will be found in a 6.00 g sample of water?

A)33.33%
B)88.81%
C)5.60%
D)33.57%
E)11.19%

Question 42

The simplest formula of a substance is found to be CH₂O,and its approximate molar mass is found by experiment to be 93 grams/mole.What is the exact molar mass of this substance in grams/mole?

A)30.0
B)87.0
C)90.1
D)93.0
E)93.1

Question 43

How many grams of O are found in 1.00 × 10² g of K₂Cr₂O₇?

A)14.9 g
B)38.1 g
C)5.44 g
D)11.3 g
E)78.8 g

Question 44

Which of the following can be one of the isomers of a compound with molecular formula C₄H₁₀?

A)2-methylpropane (methylpropane)
B)2-methylbutane
C)3-methylpentane
D)3-methylbutane
E)2-methylpentane

Question 45

A sample contains 43.7% phosphorus and 56.3% oxygen.The molar mass is 284 g/mol.What is the molecular formula of the compound?

A)P₂O₅
B)PO₃
C)P₄O₁₀
D)P₄O₅
E)P₅O₈

Question 46

Nitrogen forms at least three stable oxides: N₂O,NO,and NO₂.How many grams of nitrogen reacts with 32 grams of oxygen to form NO?

A)16 grams
B)28 grams
C)14 grams
D)32 grams
E)8 grams

Question 47

The formula mass of arachidic acid, A fatty acid found in peanut oil,is ________.

A)176.000 u
B)312.538 u
C)92.079 u
D)306.126 u
E)352.000 u

Question 48

Which of the following is the correct definition of an isomer?

A)Isomers are molecules that have the same empirical formula but different arrangements of atoms in space.
B)Isomers are molecules that have the same molecular formula but different arrangements of atoms in space.
C)Isomers are molecules that have the same arrangements of atoms in space but different empirical and molecular formulas.
D)Isomers are molecules that have the same molecular formula but contain different isotopes.
E)Isomers are molecules with the same empirical formula but have different isotopes.

Question 49

Determine the mass percent H in NH₄Cl.

A)1.9%
B)14%
C)7.5%
D)3.6%
E)67%

Question 50

What is the percentage by weight of phosphorus in calcium phosphate,Ca₃(PO₄)₂?

A)20%
B)10%
C)36%
D)29%
E)40%

Question 51

Fumaric acid,C₄H₄O₄,can be extracted from plants and can be used as a substitute for citrus acid in fruit drinks.The percent composition by mass of fumaric acid is ________.

A)C 33.33% H 33.33% O 33.33%
B)C 39.80% H 6.68% O 53.52%
C)C 40.00% H 6.67% O 53.33%
D)C 41.39% H 3.47% O 55.14%
E)C 0.25% H 0.25% O 0.50%

Question 52

How many grams of Cr are found in 1.00 × 10² g of K₂Cr₂O₇?

A)35.4 g
B)24.3 g
C)12.2 g
D)48.6 g
E)33.8 g

Question 53

How many grams of K are found in 1.00 × 10² g of K₂Cr₂O₇?

A)18.3 g
B)36.5 g
C)53.2 g
D)13.3 g
E)26.6 g

Question 54

The material Styrofoam is made by blowing a gas into the polymer polystyrene made from styrene.Styrene has the percent composition of C 92.26% and H 7.74% and 1.41*10²²
Molecules weigh 2.44 grams.What is the molecular formula for styrene?

A)CH
B)C₂H₂
C)C₈H₈
D)C₄H₄
E)C₆H₆

Question 55

The molecular formula for caffeine is C₈H₁₀O₂N₄.How many moles of C atoms are present in a 2.0 g sample of caffeine?

A)0.32 mole
B)0.27 mole
C)0.041 mole
D)0.082 mole
E)0.010 mole

Question 56

How many hydrogen atoms are there in 12.4 g of Al₂(HPO₄)₃?

A)6.55 × 10^{22 H atoms}
B)1.09 × 10^{22 H atoms}
C)6.07 × 10^{22 H atoms}
D)1.32 × 10^{23 H atoms}
E)4.39 × 10^{22 H atoms}

Question 57

Complete combustion of a 0.500 g sample of a pure hydrocarbon yielded 0.973 g CO₂ and 0.319 g H₂O.The empirical formula of this hydrocarbon is ________.

A)C₃H₅
B)C₂H₃
C)C₄H₆
D)C₅H₈
E)C₆H₉

Question 58

A 2.000 g sample of water contains 11.19% H by mass and 88.81% O by mass.What mass of H will be found in a 27.000 g sample of water?

A)3.021 g
B)1.511 g
C)2.413 g
D)1.206 g
E)23.98 g

Question 59

Which of the following substances contains the greatest number of atoms?

A)5 mol H₂O
B)6 mol CS₂
C)3 mol NaNO₃
D)2 mol NH₄OH
E)6 mol NaH

Question 60

An unknown organic compound contains carbon,hydrogen,and bromine only.The mass percentages of C and H are 12.77% C and 1.60% H.Bromine from 1.87 g of this compound has been completely converted into 3.70 g of AgBr.The molar mass of unknown organic compound is 188 u.Determine the molecular formula of the unknown.

A)CH₃Br
B)C₂H₃Br₂
C)C₂H₂Br₂
D)C₂H₂Br₄
E)C₄H₆Br₄

Question 61

Elemental analysis of 50.0000 g of a compound showed that it contained 12.7520 g C,3.2105 g H,and the rest was S.The empirical formula of this compound is ________.

A)CHS
B)CH₂S
C)CH₃S
D)C₂H₂S
E)C₂H₃S₂

Question 62

The analysis of 0.246 g of organic compound gives 0.656 g CO₂,0.134 g H₂O,and 1.86 ×10^-3 mol N₂ gas.What would be the empirical formula of this organic compound?

A)C₃H₃N
B)C₄H₄N
C)C₂H₂N₂
D)C₂H₂N
E)C₃H₃N₂

Question 63

The magnesium in a sample of mineral water weighing 110.520 g is first converted to MgNH₄PO₄ and then to Mg₂P₂O₇.The mass of Mg₂P₂O₇ obtained is 0.0216 g.Express the quantity of magnesium in the mineral water in parts per million (that is in g Mg per 10⁶ g H₂O).

A)1.95 × 10³ ppm
B)8.95 ppm
C)234 ppm
D)42.7 ppm
E)21.4 ppm

Question 64

Naphthalene,commonly found in mothballs,is 93.75% carbon and 6.25% hydrogen by mass.If naphthalene's molecular formula is twice its empirical formula,what would its molecular mass be?

A)64 u
B)96 u
C)128 u
D)192 u
E)160 u

Question 65

What is the oxidation state of chlorine in sodium hypochlorite?

A)+1
B)-1
C)+2
D)+3
E)+5

Question 66

A compound is found to have the following percent composition by mass: 38.7% K,13.8% N,47.5% O.What is the empirical formula of the compound?

A)KNO₃
B)KNO₂
C)K₂NO₂
D)K₂NO₃
E)K₂N₂O₃

Question 67

2.404 g of a compound were burned in oxygen and found to produce only 3.520 g CO₂(g),2.564 g SO₂(g)and 1.440 g H₂O(l).Determine the empirical formula of the compound.

A)CSH
B)C₂SH₄
C)C₄SH₂
D)C₂S₂H₄
E)C₂SH₂

Question 68

Maprotiline,a tetracyclic drug prescribed for the treatment of depression,has the following mass composition:
C 86.59 % , H 8.35 % , and the rest is nitrogen.
The empirical formula of maprotiline is ________.

A)C₇H₈N₃
B)C₂₀H₂₃N
C)C₈₇H₈N₅
D)C₃H₃N
E)C₁₄H₁₄N

Question 69

How many grams of H₂O are there in 10.0 g of tetraphenylarsonium chloride dihydrate,

A)0.860 g
B)0.792 g
C)0.430 g
D)0.396 g
E)0.239 g

Question 70

A 1.500 g sample of compound containing only C,H,and O was burned completely.The only combustion products were 1.738 g CO₂ and 0.711 g H₂O.What is the empirical formula of the compound?

A)CH₂O₂
B)CH₂O
C)C₂H₄O₃
D)CHO
E)CH₄O

Question 71

From the following percent by mass compositions,determine the empirical formula of the compound.
Li=18.0 %,P=26.7 %, O=55.3 %

A)LiPO₂
B)Li₃PO₄
C)LiPO₃
D)Li₃PO₃
E)LiPO₄

Question 72

The element M forms the chloride MCl₄ containing 75.0% Cl by mass.What is the molar mass of M?

A)22.7 g/mol
B)21.2 g/mol
C)11.8 g/mol
D)39.55 g/mol
E)47.3 g/mol

Question 73

4.72 g of a compound of carbon,hydrogen,and silver was burned in an atmosphere of oxygen,yielding 7.95 g of CO₂,1.02 g of H₂O,and 3.02 g of a mixture of silver and silver oxide.Because the production of this mixture yielded an indeterminate value for the amount of silver,another sample of the compound weighing 8.12 g was reacted with a solution of NaCl,yielding 5.57 g of AgCl.What is the empirical formula of the compound?

A)C₅H₅Ag
B)C₈H₈Ag
C)C₈H₅Cl
D)C₈H₅Ag
E)C₅H₈Ag

Question 74

A strip of electrolytically purified copper weighing 3.178 grams is strongly heated in a stream of oxygen until it is all converted to a black oxide.The resultant black powder weighs 3.978 g.What is the formula of the oxide?

A)CuO₂
B)Cu₂O₃
C)CuO₃
D)Cu₂O
E)CuO

Question 75

A 4.05 g sample of a compound containing only C,H,and O was burned completely.The only combustion products were 10.942 g CO₂ and 4.476 g H₂O.What is the empirical formula of the compound?

A)C₇H₁₄O
B)C₇H₇O
C)C₇H₁₄O₇
D)CH₂O
E)C₆H₁₂O

Question 76

To produce ferrocene one requires 2.33 g of C₅H₅ (65.0 g/mol)for every 1.00 g of Fe used (55.9 g/mol).What is the value of x in the formula of ferrocene:

A)1
B)2
C)3
D)4
E)5

Question 77

An organic compound contains C,H,and O.The percentages of H and C are 6.73% H,and 39.99% C by mass.The molecular mass is 60.06 u.What is the molecular formula of the compound?

A)CH₂O
B)C₃H₆O3
C)C₂H₃O₂
D)C₂H₄O₂
E)C₄H₈O₄

Question 78

The molecular formula for a sugar molecule is C₁₂H₂₂O₁₁.What is the percent of carbon in the molecule?

A)2.37%
B)67.88%
C)42.12%
D)8.34%
E)26.67%

Question 79

The complete combustion of 0.285 g of a pure hydrocarbon yielded 0.878 g CO₂ and 0.405 g H₂O.What is the mass % C in this hydrocarbon?

A)27.3%
B)24.0%
C)84.1%
D)32.4%
E)72.7%

Question 80

A compound has the following percentage composition,by weight: 22.0% Cu,12.9% Fe,16.6% C,19.4% N,and 29.1% H₂O.Write a plausible (empirical)formula for this hydrate.

A)CuFe(CN)₄ ∙ 4 H₂O
B)CuF(CN)₄ ∙ 5 H₂O
C)Cu₃Fe₂(CN)₁₂ ∙ 14 H₂O
D)CuF(CN)4
E)Cu₃Fe₂(CN)₁₂