Question 1

Why does an atom with many valence electrons tend to gain electrons rather than lose any?

Accepted Answer

A)  Atoms with many valence electrons tend to have relatively weak forces of attraction between the valence electrons and the nucleus. Therefore, the outer electrons are free to attract other electrons.
B)  There is stability in numbers. Atoms with many valence electrons are always attracting new electrons.
C)  The old adage that "he who has, gets" is also true in atomic structure. Atoms with many valence electrons can essentially overpower atoms with few valence electrons and attract additional electrons.
D)  Atoms with many valence electrons tend to have relatively strong forces of attraction between the valence electrons and the nucleus. This makes it easy for them to gain additional electrons.

Question 2

If you were to increase the pressure of a gas above a liquid (such as by pressing a piston above a liquid) what happens?

Accepted Answer

A)  The gas is forced into solution and the solubility increases.
B)  The solution is compressed and the gas is forced out of the solvent.
C)  The pressure goes down and the gas moves out of the solvent.
D)  The pressure goes down and the gas goes into the solvent.
E)  The amount of gas in the solution would stay the same.

Question 3

Why is it better to recycle metals than to mine more?

Accepted Answer

A)  It takes far less energy to recycle.
B)  Mining is less expensive than recycling but not environmentally friendly.
C)  Ores contain toxic elements.
D)  all of the above
E)  none of the above

Question 4

Would you expect a hydrogen atom with three electrons to be more chemically reactive or less chemically reactive than a hydrogen atom with two electrons? Briefly explain.

Accepted Answer

A hydrogen atom with three electrons wou...

Question 5

What is the molarity of 0.5 liters of a solution with five moles of sucrose in it?

Accepted Answer

A)  10 molar
B)  0) 5 molar
C)  5 molar
D)  2) 5 molar
E)  1 molar

Question 6

Which of the following statements is true?

Accepted Answer

A)  Not all of the electrons in the valence shell are valence electrons.
B)  The valence shell is usually the most unreactive shell.
C)  The valence shell always gives us the electron dot structure.
D)  The electron dot structure is made up of each of the valence shells.
E)  none of the above

Question 7

Which of the following solutions is the most concentrated?

Accepted Answer

A)  one liter of water with 1 gram of sugar
B)  one liter of water with 2 grams of sugar
C)  one liter of water with 5 grams of sugar
D)  one liter of water with 10 grams of sugar
E)  They all have the same volume.

Question 8

Water, H2O, and methane, CH4 have about the same mass and differ by only one type of atom. Why is the boiling point of water so much higher than that of methane?

Accepted Answer

A)  The water molecule is less symmetrical than is the methane molecule.
B)  The oxygen of a water molecule has two lone pairs of electrons.
C)  The electronegativity difference between oxygen and hydrogen is greater than the electronegativity difference between carbon and hydrogen.
D)  all of the above

Question 9

Which of the following molecules would you expect to be the least attracted to a Na+ ion?

Accepted Answer

A)  H-F
B)  H₃C-CH₃
C)  Cl2CH₂
D)  F-
E)  HO-

Question 10

MgCl2 crystals are composed of

Accepted Answer

A)  units of MgCl2 molecules held together by dipole interactions.
B)  groups of Mg2+ ions and Cl2 molecules.
C)  units composed of six Mg atoms and six Cl2 molecules.
D)  a multitude of Mg2+ ions and Cl- ions grouped together in a three-dimensional array with a 1:2 ratio of Mg2+ to Cl-.
E)  a two-dimensional array of [-Mg-Cl-Cl-] units.

Question 11

What is a molecule?

Accepted Answer

A)  a group of atoms that are held together by covalent bonds
B)  a group of atoms that are held together by ionic bonds
C)  a pair of atoms sharing a set of valence electrons
D)  a pair of shared valence electrons
E)  a group of covalent compounds held together by ionic bonds

Question 12

What is molarity?

Accepted Answer

A)  the number of moles of solute per liter of solution
B)  the number of grams of solute per liter of solution
C)  the number of moles of solute per liter of solvent
D)  the number of liters of solute per mole of solution
E)  none of the above

Question 13

Which of the following would be considered a homogeneous mixture?

Accepted Answer

A)  wine
B)  hydrogen cyanide
C)  rusty iron
D)  pretzel
E)  sugar

Question 14

How many moles of water are there in 100. grams of water?

Accepted Answer

A)  1800 moles
B)  100 moles
C)  0) 018 moles
D)  5) 55 moles

Question 15

What do chicken noodle soup and garden soil have in common?

Accepted Answer

A)  They are both examples of heterogeneous mixtures.
B)  They both contain elements.
C)  They are both examples of compounds.
D)  nothing

Question 16

Magnesium ions carry a 2+ charge, and chloride ions carry a 1- charge. What is the chemical formula for the ionic compound magnesium chloride?

Accepted Answer

A)  MgCl
B)  Mg2Cl
C)  MgCl2
D)  Mg2Cl2

Question 17

Which of the following is an ion?

Accepted Answer

A)  2 H₂
B)  Br2
C)  HCl
D)  Au + 3 Br2
E)  none of the above

Question 18

Classify the following bonds as ionic, covalent, or neither (O, atomic number 8; F, atomic number 9; Na, atomic number 11; Cl, atomic number 17; U, atomic number 92) . O with F Ca with Cl Na with Na

Accepted Answer

A)  covalent, ionic, covalent
B)  ionic, covalent, neither
C)  neither, ionic, covalent
D)  covalent, ionic, neither

Question 19

Which would you expect to have a higher melting point: sodium chloride, NaCl, or aluminum oxide, Al2O3?

Accepted Answer

A)  The aluminum oxide has a higher melting point because it is a larger molecule and has a greater number of molecular interactions.
B)  NaCl has a higher melting point because it is a solid at room temperature.
C)  The aluminum oxide has a higher melting point because of the greater charges of the ions, and hence the greater force of attractions between them.
D)  The aluminum oxide has a higher melting point because of the covalent bonds within the molecule.

Question 20

Which of the following describes how a metal atom behaves in a bulk metallic object?

Accepted Answer

A)  The metal ion shares its outermost electrons freely with its neighbors.
B)  The metal atoms have limited interaction with neighboring atoms.
C)  The metal atom shares its electrons in a very directional manner.
D)  The metal atom shares its electrons with only one other atom.
E)  none of the above

Exam 12: Chemical Bonds and Mixtures

Why does an atom with many valence electrons tend to gain electrons rather than lose any?

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Magnesium ions carry a 2+ charge, and chloride ions carry a 1- charge. What is the chemical formula for the ionic compound magnesium chloride?

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If you were to increase the pressure of a gas above a liquid (such as by pressing a piston above a liquid) what happens?

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MgCl2 crystals are composed of

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Why is it better to recycle metals than to mine more?

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What do chicken noodle soup and garden soil have in common?

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Which of the following describes how a metal atom behaves in a bulk metallic object?

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How many moles of water are there in 100. grams of water?

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Which of the following statements is true?

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What is the molarity of 0.5 liters of a solution with five moles of sucrose in it?

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Water, H2O, and methane, CH4 have about the same mass and differ by only one type of atom. Why is the boiling point of water so much higher than that of methane?

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Which of the following is an ion?

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Which of the following would be considered a homogeneous mixture?

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Which of the following molecules would you expect to be the least attracted to a Na+ ion?

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Which of the following solutions is the most concentrated?

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Classify the following bonds as ionic, covalent, or neither (O, atomic number 8; F, atomic number 9; Na, atomic number 11; Cl, atomic number 17; U, atomic number 92) . O with F Ca with Cl Na with Na

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Which would you expect to have a higher melting point: sodium chloride, NaCl, or aluminum oxide, Al2O3?

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Would you expect a hydrogen atom with three electrons to be more chemically reactive or less chemically reactive than a hydrogen atom with two electrons? Briefly explain.

Correct AnswerverifiedA hydrogen atom with three electrons wou...View AnswerShow Answer

What is a molecule?

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What is molarity?

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MgCl₂ crystals are composed of

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Water, H₂O, and methane, CH₄have about the same mass and differ by only one type of atom. Why is the boiling point of water so much higher than that of methane?

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Which would you expect to have a higher melting point: sodium chloride, NaCl, or aluminum oxide, Al₂O₃?

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A hydrogen atom with three electrons wou...
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