Deck 6: Chemical Composition

Question 1

Avogadro's Number is 6.022 × 10²³.

Answer 1

True

Question 2

The lighter the atom,the less mass in one mole of that atom.

Answer 2

True

Question 3

One mole of copper atoms is 6.022 × 10²³ copper atoms.

Answer 3

True

Question 4

One mole of nitrogen gas contains (2)× (6.022 × 10²³)nitrogen atoms.

Question 5

The number 6.022 × 10²³ is six times larger than the number 6.022 × 10²².

Question 6

The mole has a value of 6.023 × 10²².

Question 7

The chemical formula clearly indicates the relationship between the mass of each element in the formula.

Question 8

One mole of lead(II)nitrate contains six moles of oxygen atoms.

Question 9

Mass is used as a method of counting atoms.

Question 10

The numerical value of the mole is defined as being equal to the number of atoms in exactly 12 grams of pure carbon-12.

Question 11

Six grams of carbon contains 3.008 × 10²³ atoms.

Question 12

The mass of 2.0 moles of H₂O is greater than the mass of 1.0 mole of CO₂.

Question 13

One mole of water contains 16 grams of oxygen atoms.

Question 14

One mole of zinc contains 65.39 zinc atoms.

Question 15

One mole of chlorine gas has a mass of 35.45 grams.

Question 16

One mole of CO₂ gas contains 1 mole of carbon atoms and 2 moles of oxygen atoms.

Question 17

Two moles of cobalt atoms have a mass of 117.87 grams.

Question 18

One mole of water contains 6.022 × 10²³ hydrogen atoms.

Question 19

One mole of I₂ has more atoms in it than one mole of Na.

Question 20

One mole of argon has more atoms in it than one mole of neon.

Question 21

The correct formula for calculating mass percent of X in compound XY is:
= Mass % X

Question 22

Water is 11.2% hydrogen by mass.

Question 23

What is the correct value for Avogadro's number?

A)6.022 × 10²³
B)6.022 × 10³³
C)6.023 × 10²²
D)6.022 × 10^2.3
E)none of the above

Question 24

The molar mass of a compound serves as a conversion factor between grams and moles.

Question 25

The empirical formula mass is 18.0 and the molecular formula mass is 90,therefore n = 5.

Question 26

The empirical formula mass must be 25.0 if the molecular formula mass is 250 and n = 5.

Question 27

Which of the following statements about the mole is FALSE?

A)The size of a mole of atoms has a reasonable mass.
B)A mole of a monatomic element corresponds to one Avogadro's number of atoms.
C)One mole of a monatomic element has a mass equal to its atomic mass expressed in grams.
D)One mole of water contains 1/2 mole of oxygen atoms.
E)none of the above

Question 28

How many moles of Cu are in 1.48 × 10²⁵ Cu atoms?

A)0.0408
B)24.6
C)1.54 × 10²⁵
D)6.022 × 10²³
E)none of the above

Question 29

C₂H₆O₃ could be an empirical formula.

Question 30

C₂H₆O₄ could be an empirical formula.

Question 31

The molecular formula is equal to the empirical formula multiplied by a whole number integer.

Question 32

An empirical formula gives the specific number of each type of atom in a molecule.

Question 33

An empirical formula gives the smallest whole number ratio of each type of atom in a molecule.

Question 34

How many atoms are in 1.50 moles of fluorine gas?

A)6.022 × 10²³
B)9.03 × 10²³
C)18.98
D)1.81 × 10²⁴
E)none of the above

Question 35

A molecule that has an empirical formula of HO and a molar mass of 34.02 gram must have a molecular formula of H₂O₂.

Question 36

C₂H₃O₂ could be an empirical formula.

Question 37

The empirical formula for C₆H₆ is C₃H₃.

Question 38

There are 6 grams of carbon in 22 grams of carbon dioxide.

Question 39

The chemical formula CuBr₂ indicates that this compound is composed of 1 gram of copper and 2 grams of bromine.

Question 40

How many atoms are in 5.80 moles of He?

A)6.02 × 10²³
B)1.03 × 10²³
C)4.00
D)3.49 × 10²⁴
E)none of the above

Question 41

What is the mass of 1.56 × 10²¹ atoms of magnesium in grams?

A)4.72 × 10^-5
B)0.0630
C)0.142
D)1.07 × 10^-4
E)none of the above

Question 42

What is the mass in grams of 5.40 moles of lithium?

A)6.94
B)37.5
C)1.29
D)3.25 × 10²⁴
E)none of the above

Question 43

How many molecules of sulfur trioxide are in 78.0 grams?

A)5.87 × 10²³
B)7.33 × 10²³
C)3.76 × 10²⁷
D)0.974
E)none of the above

Question 44

You have 10.0 g each of Na,C,Pb,Cu and Ne.Which contains the smallest number of moles?

A)Na
B)C
C)Pb
D)Cu
E)Ne

Question 45

Which of the following contains 9.02 × 10²³ atoms?

A)4.00 g H₂
B)9.00 g H₂O
C)28.0 g N₂
D)32.0 g O₂
E)none of the above

Question 46

In comparing 1 mole of carbon atoms to one mole of magnesium atoms,which statement is TRUE?

A)The mass of 1 mole of carbon is greater than the mass of 1 mole of magnesium.
B)The mass of 1 mole of magnesium is greater than the mass of 1 mole of carbon.
C)The mass of 1 mole of carbon is the same as the mass of 1 mole of magnesium.
D)There are more atoms in 1 mole of magnesium than in 1 mole of carbon.
E)none of the above

Question 47

How many hydrogen atoms are in 35.0 grams of hydrogen gas?

A)4.25 × 10²⁵
B)2.09 × 10²⁵
C)2.12 × 10²⁵
D)1.05 × 10²⁵
E)none of the above

Question 48

In comparing a balloon containing 25 grams of helium to a balloon containing 25 grams of neon,which one of the following statements is TRUE?

A)Each balloon has an equal number of atoms.
B)The helium balloon has more atoms.
C)The neon balloon has more atoms.
D)This scenario cannot happen because gases have no mass.
E)none of the above

Question 49

What is the mass of 3.09 × 10²⁴ atoms of sulfur in grams?

A)9.64 × 10²²
B)9.91 × 10²⁵
C)165
D)0.160
E)none of the above

Question 50

How many moles are there in 82.5 grams of iron?

A)4.97 × 10²⁵
B)55.85
C)0.677
D)1.48
E)none of the above

Question 51

How many moles of iron are contained in 1.75 kg of iron?

A)3.13 × 10^-2
B)3.13 × 10^-4
C)31.3
D)3.13 × 10⁴
E)none of the above

Question 52

What is mass of 0.560 moles of chlorine gas?

A)19.9
B)63.3
C)127
D)39.7
E)none of the above

Question 53

One mole of oxygen gas has a mass of ________ g.

A)16.0
B)32.0
C)6.022 × 10²³
D)8
E)none of the above

Question 54

One mole of boron has a mass of ________ g.

A)9.012
B)6.022 × 10²³
C)5
D)10.811
E)none of the above

Question 55

How many moles are there in 17.5 grams of sodium?

A)22.99
B)1.05 × 10²⁵
C)0.761
D)1.31
E)none of the above

Question 56

You have 10.0 g each of Na,C,Pb,Cu and Ne.Which contains the largest number of moles?

A)Na
B)C
C)Pb
D)Cu
E)Ne

Question 57

How many moles of Pb are in 4.71 × 10²¹ Pb atoms?

A)0.00782
B)2.84 × 10⁴⁵
C)207.2
D)6.022 × 10²³
E)none of the above

Question 58

How many moles of bromine gas are in 37.7 grams?

A)0.236
B)0.472
C)3.01 × 10³
D)79.9
E)none of the above

Question 59

The mass of one mole of carbon dioxide is ________ g.

A)28.01
B)384.4
C)32.00
D)44.01
E)none of the above

Question 60

How many atoms are in 15.6 grams of silicon?

A)2.64 × 10²⁶
B)3.34 × 10²³
C)0.555
D)438
E)none of the above

Question 61

Bauxite is an ore that contains the element aluminum.If you obtained 108 grams of aluminum from an ore sample that initially weighed 204 grams,what is the mass percent of aluminum in this bauxite ore?

A)52.9
B)15.6
C)0.53
D)47.1
E)none of the above

Question 62

If 3.011 × 10²³ molecules have a mass of 20.04 grams,what is the molar mass of this substance?

A)40.08 g/mol
B)10.02 g/mol
C)20.04 g/mol
D)6.658 × 10^-23 g/mol
E)none of the above

Question 63

Calculate the molar mass of calcium nitrate.

A)136.03 g/mol
B)102.09 g/mol
C)132.10 g/mol
D)164.10 g/mol
E)none of the above

Question 64

One mole of ammonium nitrite contains:

A)2 moles of nitrogen atoms.
B)4 moles of hydrogen atoms.
C)2 moles of oxygen atoms.
D)All of A,B,and C.
E)None of A,B,and C.

Question 65

How many moles of carbon are in 3.5 moles of calcium carbonate?

A)10.5
B)3.5
C)7
D)100.09
E)none of the above

Question 66

Calculate the molar mass of ammonium carbonate.

A)78.05 g/mol
B)88.05 g/mol
C)96.09 g/mol
D)112.09 g/mol
E)none of the above

Question 67

What is the mass percent of chlorine in hydrochloric acid?

A)2.8
B)35.5
C)97.2
D)70.1
E)none of the above

Question 68

How many molecules of nitrogen monoxide are in a 22.5 gram sample?

A)5.86 × 10²³
B)7.33 × 10²³
C)4.51 × 10²³
D)4.06 × 10²³
E)none of the above

Question 69

If 2.01 × 10²³ atoms of an element from Group IA of the periodic table has a mass of 7.675 grams,this element is most likely

A)Li.
B)Na.
C)K.
D)Rb.
E)Cs.

Question 70

An iron ore sample is found to be 35.00% Fe by mass.How many grams of ore are needed to obtain
Of Fe?

A)1297
B)158.9
C)295.1
D)350.0
E)none of the above

Question 71

One mole of potassium sulfate contains:

A)4 moles of oxygen.
B)2 moles of sulfur.
C)1 mole of potassium.
D)3 moles of potassium.
E)none of the above

Question 72

One mole of (NH₄)₂HPO₄ contains how many moles of hydrogen atoms?

A)4
B)2
C)8
D)9
E)none of the above

Question 73

How many moles of fluorine are in 3.2 moles of xenon hexafluoride?

A)22.4
B)12.8
C)19.2
D)16
E)none of the above

Question 74

What is the mass percent of hydrogen in water?

A)33.3
B)88.8
C)5.60
D)11.2
E)none of the above

Question 75

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)3.8
C)7.6
D)11.4
E)none of the above

Question 76

One mole of ammonium nitrate contains:

A)3 moles of hydrogen.
B)2 moles of oxygen.
C)2 moles of nitrogen.
D)1 mole of nitrogen.
E)none of the above

Question 77

A 15.5 gram sample of diphosphorous pentoxide contains how many grams of phosphorous?

A)3.38
B)1.69
C)6.76
D)13.5
E)none of the above

Question 78

A 500.gram iron ore sample was determined to contain 242 grams of iron.What is the mass percent of iron in the ore?

A)93.7
B)48.4
C)51.6
D)32.6
E)none of the above

Question 79

A 42.7 gram sample of potassium nitrate contains how many grams of potassium?

A)39.1
B)16.5
C)21.4
D)8.54
E)none of the above

Question 80

What is the molar mass of aluminum sulfate?

A)123.0 g/mol
B)278.0 g/mol
C)306.2 g/mol
D)315.2 g/mol
E)342.2 g/mol