Chemistry Chapter Test:The Mole

the number of grams of an element that is numerically equal to the atomic mass of the element in AMU

Atomic Mass

the number of representative particles of a substance present in 1 mole of that substance

Avogadro's number

the mass of a mole of any element or compound

Molar Mass

The volume occupied by a mole of any gas at STP

Molar Volume

Avogadro's number of representative particles is equal to one __. a.mole b.kilogram c.gram d.kelvin

a. mole

What SI unit is used to measure the number of representative particles in a substance? a.mole b.ampere c.kelvin d.kilogram

a. mole

Which of the following gas samples would have the largest number of representative particles at STP? a.nitrogen b.sulfur c.lithium d.neon

a. nitrogen

How many atoms are in 3.5 moles of arsenic atoms? a.2.1 x 10²³ atoms b.5.8 x 10⁻²⁴ c.1.7 x 10²³ atoms d.7.5 x 10¹ atoms

a.2.1 x 10²³ atoms

How many moles of CaBr₂ are in 5.0 grams of CaBr₂? a.2.5 x 10⁻² mol b.1.0 x 10³ mol c.4.2 x 10⁻² mol d.4.0 x 10¹ mol

a.2.5 x 10⁻² mol

What is the number of moles in 500 L of He gas at STP? a.22 mol b.90 mol c.0.2 mol d.0.05 mol

a.22 mol

How many hydrogen atoms are in 5 molecules of isopropyl alcohol,C₃H₇0? a.35 b.35 x (6.02 x 10²³) c.5 x (6.02 x 10²³) d.5

a.35

What is the number of moles of beryllium atoms in 36 g of Be? a.4.0 mol b.45.0 mol c.0.25 mol d.320 mol

a.4.0 mol

If 20.0 grams of Ca combines completely with 16.0 grams of S to form a compound, what is the percent composition of Ca in the compound? a.55.6 % b.20.0 % c.44.4% d.1.25%

a.55.6 %

What is the density at STP of the gas sulfur hexafluoride, SF₆? a.6.52 g/L b.3270 g/L c.3.93 x 10²⁴ g/L d. 0.153 g/L

a.6.52 g/L

What is the percent by mass of carbon in acetone, C₃H₆O? a.62.1% b.20.7% c.1.61% d.30.0%

a.62.1%

Which of the following compounds has the lowest percent gold content by weight? a.AuI₃ b.AuOH c.Au(OH)₃ d.AuCl₃

a.AuI₃

What is the empirical formula of a substance that is 53.5% C, 15.5% H and 31.1% N by weight? a.C₂H₈N b.C₃HN c.CH₄N₇ d.C₄H₁₄N₂

a.C₂H₈N

Which of the following is NOT an empirical formula? a.C₂N₂H₈ b.Sb₂S₃ c.BeCr₂O₇ d.C₃H₈O₈

a.C₂N₂H₈

Which of the following compounds has the highest oxygen content, by weight a.H₂O b.CO₂ c.BaO d.Na₂O

a.H₂O

Which of the following is NOT true about empirical and molecular formula? a. The empirical formula of a compound can be triple its molecular formula b. Several compounds can have the same empirical formula, but have different molecular formulas c. The molecular formula of a compound can be the same as its empirical formula d. The molecular formula of a compound can be some whole-number multiple of its empirical formula

a.The empirical formula of a compound can be triple its molecular formula

The atomic masses of any two elements contain the same number of ______. a.atoms b.grams c.milliliters d.ions

a.atoms

A 22.4-L sample of which of the following substances, at STP, would contain 6.02 x 10²³ representative particles? a.oxygen b.gold c.cesium iodide d.sulfur

a.oxygen

What is the mass of oxygen in 250 g of sulfuric acid, H₂SO₄? a.3.9 g b.160 g c.0.65 g d.16 g

b. 160 g

What is the volume, in liters, of 0.500 mol of C₃H₈ gas at STP? a.0.0335 l b.11.2 L c.22.4 L d.16.8 L

b.11.2 L

Which of the following gas samples would have the largest number of representative particles at STP? a.0.10 L Xe b.12.0 L He c.0.007 L SO₃ d.7.0 L O₂

b.12.0 L He

What is the mass of silver in 3.4 g AgNo₃? a.3.0 g b.2.2 g c.0.025 g d.0.64 g

b.2.2 g

The molar mass of a certain gas is 49 g. What is the density of the gas in g/L at STP? a.3.6 x 10⁻²⁴ g/L b.2.2 g/L c.0.46 g/L d.71 g/L₀

b.2.2 g/L

What is the percent composition of chromium in BaCrO₄? a.4.87% b.20.5% c.25.2% d.9.47%

b.20.5%

How many moles of silver atoms are in 1.8 x 10²⁰ atoms of silver? a.3.3 x 10⁻³ b.3.0 x 10⁻⁴ c.1.1 x 10⁴⁴ d.3.0 x 10²

b.3.0 x 10⁻⁴

How many moles of tungsten atoms are in 4.8 x 10²⁵ atoms of tungsten? a. 8.0 x 10² moles b.8.0 x 10¹ moles c.1.3 x 10⁻¹ moles d.1.3 x 10⁻³ moles

b.8.0 x 10¹ moles

What is the percent composition of carbon, in heptane, C₇H₁₆? a.19% b.84% c.68% d.12%

b.84%

The ratio of carbon atoms to hydrogen atoms to oxygen atoms in a molecule of dicyclohexyl maleate is to 4 to 6 to 1. What is its molecular formula if its molar mass is 280 g? a.C₂H₁₂O₂ b.C₁₆H₂₄O₄ c.C₄H₆O₁ d.C₁₂H₁₈O₃

b.C₁₆H₂₄O₄

The lowest whole number ratio of elements in a compound is called the ___. a.representative formula b.empirical formula c.molecular formula d.binary formula

b.empirical formula

For which of the following conversions does the value of the conversion factor depend upon the formula of the substance? a.moles of any substance to number of particles b.mass of any substance to mole c.volume of gas (STP) to moles d.density of gas (STP) to molar mass

b.mass of any substance to mole

To determine the formula of a new substance, one of the first steps is to find the _______. a.molar mass b.percent composition c.volume at STP d.number of particles per mol

b.percent composition

The molar mass of a gas can be determined from which of the following? a.the volume of a mole of gas b.the density of the gas at STP c.Avogadro's number d.none of the above

b.the density of the gas at STP

What information is needed to calculate the percent composition of a compound? a.The weight of the sample to be analyzed and its molar volume b.the formula of the compound and the atomic mass of its elements c.the formula of the compound and its density d. the weight of the sample to be analyzed and its density

b.the formula of the compound and the atomic mass of its elements

What is true about the molar mass of nitrogen gas? a.the molar mass is 14.0 g b.the molar mass is 28.0 g c.the molar mass is equal to the massof one mole of nitrogen atom d.none of the above

b.the molar mass is 28.0 g

All of the following are equal to Avogadro's number EXCEPT ___. a.the number of molecules of nitrogen in 1 mol N₂ b.the numbers of atoms of bromine in 1 mol of Br₂ c.the number of molecules of carbon monoxide in 1 mol CO d.the number of atoms of gold in 1 mol Au

b.the numbers of atoms of bromine in 1 mol of Br₂

Which expression represents the percent by mass of nitrogen in NH₄NO₃? a. 80 g NH₄NO₃/14 g N x 100% b. 14 g N/80 g NH₄NO₃ x 100% c. 28 g N/80 g NH₄NO₃ x 100% d.80 g NH₄NO₃/28 g N x 100%

c. 28 g N/80 g NH₄NO₃ x 100%

What is the number of moles in 9.63 L of H₂S gas at STP? a.3.54 mol b.14.7 mol c.0.430 mol d.0.104 mol

c.0.430 mol

How many molecules are in 2.10 mol CO₂ a.2.53 x 10²⁴ molecules b.3.49 x 10⁻²⁴ molecules c.1.26 x 10²⁴ molecules d.3.79 x 10²⁴ molecules

c.1.26 x 10²⁴ molecules

How many atoms are in 0.075 mol of titanium? a.6.4 x 10² b.1.2 x 10⁻²⁵ c.4.5 x 10²² d.2.2 x 10²⁴

c.4.5 x 10²²

What is the mass in grams of 5.90 mol C₈H₁₈? a.19.4 g b.389 g c.673 g d.0.0512 g

c.673 g

If 60.2 grams Hg combines completely with 24.0 grams of Br to form a compound, what is the percent composition of Hg in the compound? a.60.1% b.39.9% c.71.5% d.28.5%

c.71.5%

Which of the following sets of empirical formula, molar mass, and molecular formula is correct? a.CaO, 56 g, Ca₂O₂ b.CH, 78 g, C₁₃H₁₃ c.CH₄N, 90 g, C₃H₁₂N₃ d.C₃H₈O,120 g, C₃H₈O₂

c.CH₄N, 90 g, C₃H₁₂N₃

Which of the following compounds have the same empirical formula? a.C₆H₁₂ and C₆H₁₄ b.C₄H₁₀ and C₁₀H₄ c.C₇H₁₄ and C₁₀H₂₀ d.CO₂ and SO₂

c.C₇H₁₄ and C₁₀H₂₀

if the density of a noble gas is 0.902 g/L at STP, that gas is ____. a.Kr b.Ar c.Ne d.Xe

c.Ne

What is the empirical formula of a compound that is 40% sulfur and 60% oxygen by weight? a.S₆O₄ b.SO c.SO₃ d.SO₂

c.SO₃

Which of the following is NOT a true statement about atomic mass? a.The atomic mass is the mass of one mole of atoms b.The atomic mass is found by checking the periodic table c.The atomic mass is 12 g for magnesium d.The atomic mass is the number of grams of an element that is numerically equal to the mass in amu

c.The atomic mass is 12 g for magnesium

Which of the following is NOT a representative particle? a.cation b.anion c.atom d.all of the above

c.atom

The molar mass of C₇H₁₆ and the molar mass of CaCO₃ contain approximately the same number of_____. a.carbon atoms b.cations c.grams d.anions

c.grams

The mass of a mole of NaCl is the ________. a. atomic mass b. molecular mass c.molar mass d.gram atomic mass

c.molar mass

Which combination of temperature and pressure correctly describes standard temperature and pressure, STP? a.100°C and 100kPa b.1°C and 0kPa c.0°C and 22.4 kPa d.0°C and 101 kPa

d.0°C and 101 kPa

What is the number of moles in 432 g Ba(NO₃)₂ a.3.66 mol b.0.237 mol c.0.605 mol d.1.65 mol

d.1.65 mol

Butanol is composed of carbon, hydrogen, and oxygen. If 1.0 mol of butanol contains 6.0 x 10²⁴ atoms of hydrogen, what is the subscript for the hydrogen atom in C₄H₂O? a.1 b.6 c.8 d.10

d.10

The molar volume of a gas at STP occupies _____. a.0°C b.12 grams c. 1 kilopas cal d.22.4 L

d.22.4 L

What is the molar mass of AuCl₃? a.96 g b.130 g c.232.5 g d.303.6 g

d.303.6 g

If the density of an unknown gas Z is 4.50 g/L at STP, what is the molar mass of gas Z? a.26.9 g/mol b.0.201 g/mol c.101 g/mol d.5.00 g/mol

d.5.00 g/mol

What is the molar mass of (NH₄)₂CO₃? a.138 g b.78 g c.144 g d.96 g

d.96 g

Given 1.00 mole of each of the following gases at STP, which gas would have the greatest volume? a.He b.SO₃ c.O₂ d.All would have the same volume

d.All would have the same volume

The molar mass of a substance can be calculated from its density alone, if that substance is a(n)____. a.solid b.liquid c.element d.gas at STP

d.gas at STP

The volume of one mole of a substance is 22.4 L at STP for all ________. a.solids b.compounds c.liquids d.gases

d.gases

the smallest whole number ratio of the atoms in a compound

empirical formula

the SI unit used to measure amount of substance

mole

the percent by mass of each element in a compund

percent composition

an atom,an ion or a molecule, depending upon the way a substance commonly exists

representative particle

0°C and 1 atm

standard temperature and pressure