Chemistry Chapter 4

Which of the following statements correctly describes water as a solvent? Select all that apply.
A.    Water can dissolve many ionic substances.
B.    Water is a molecule; therefor it can dissolve other molecular solute only.
C.    Water usually simply acts as a dispersing medium for solutes.
D.    Water as a solvent often plays an active role in the chemical reactions of solutes.

Which of the following chemical equations correctly represents the dissociation of K₂SO₄ of water?
A.    K₂SO₄ (s) → 2K⁺ (aq) + S^2- (aq) + 4O^2- (aq)
B.    K₂SO₄ (s) → K₂²⁺ (aq) + SO₄^2- (aq)
C.    K₂SO₄ (s) → 2K⁺ (aq) + SO₄^2- (aq)
D.    K₂SO₄ (s) → K₂⁺ (aq) + SO₄^2- (aq)

Which of the following statements correctly describes a molecular equation? Select all the apply.
A.    This equation only shows molecular substances that participate in a reaction.
B.    This equation gives the most accurate representation of the chemical charges taking place.
C.    A molecular equation will not include any charges of any of the species.
D.    This equation represents all reactants and products as if they were intact and undissociated.

In general, covalent compounds that are _____ will be soluble in water.  These compounds do not _____ into ions, and are therefore nonelectrolytes.

A substance that conducts an electric current when dissolved in water is called a(n) ______.

Which Statements correctly describes the amounts of the different ions present in 1.52 L of a 0.350 M solution of CaCl₂?  Select all that apply.
A.    The concentration of Ca²⁺ ions is equal to 0.117 M.
B.    The concentration of Cl^- ions is equal to 0.700 M.
C.    There are 0.350 mol of Cl^- present.
D.    There are 4.34 mol of Ca²⁺ ions present.
E.    There are 0.532 mol of Ca²⁺ ions present.

In a covalent bond between identical atoms, the electrons are shared           between the atoms.  If the atoms are not identical the electron distribution is           so that the electrons are closer to one atom than the other.  This type of bond is called a(n)            covalent bond.

Which of the following statements correctly describes a total ionic equation?  Select all that apply.
A.    The total ionic equation includes all ions, including spectator ions.
B.    All species must show charges in this type of equation.
C.    Charges and atoms must be balanced in this type of equation.
D.    This equation shows only the ions involved in a reaction.
E.    Charges must be included where relevant in this type of equation.

When an ionic compound is added to water, the          will be attracted to the partially positive H atom of water and the         will be attracted to the partially negative O atom of water.  As the compound dissolves the ions separate from each other, or          .

Which of the following options correctly defines an electrolyte?
A.    A substance that dissolves in water.
B.    A substance that is found in a biological solution.
C.    A substance that conducts an electric current in an aqueous solution.
D.    A substance that conducts electricity.

Why does an aqueous solution of an ionic substance conduct an electric current?
A.    Water conducts electricity.
B.    The solution contains free electrons that can carry a current.
C.    An ionic substance contains a metal, and metals conduct electricity.
D.    The solution contains ions that are free to move.

Match the symbols correctly to describe the uneven charge distribution in one O-H bond of the H₂O molecule.

1.   Partially negatively charged (δ-)
2.   Partially positively charged (δ+)
A.   H
B.   O

Which features make H₂O a polar molecule?  Select all that apply.
A.   The molecule has a bent molecular shape.
B.   The molecule has an uneven distribution of electron density.
C.   Each H₂O molecule has a different shape.
D.   The molecule is electrically charged.
E.   The electrons are distributed unevenly within each bond of the molecule.

Three equations representing a chemical reaction are shown.  Classify each equation according to type.
1.   Pb²⁺ (aq) + 2NO₃^- (aq) + 2Na⁺ (aq) + 2Cl^- (aq) → PbCl₂ (s) + 2Na⁺ (aq) + 2No₃^- (aq)
2.   Pb(NO₃)₂ (aq) + 2NaCl (aq) → PbCl₂ (s) + 2NaNO₃ (aq)
3.   Pb²⁺ (aq) + 2Cl^- (aq) → PbCl₂ (s)
A.   Total Ionic Equation
B.   Molecular Equation
C.   Net Ionic Equation

An electric current requires the movement of         particles, which could be electrons or ions.  A solid ionic substance does not conduct an electric current because the ions are          in place in the crystal structure.  When dissolved in water, the ions           and are therefore free to move.

Which of the following statements correctly describe the role of water as a solvent?  Select all that apply.
A.    Water can dissolve many ionic substances.
B.    Water usually simply acts as a dispersing medium for solutes.
C.    Water as a solvent often plays an active role in the chemical reactions of solutes.
D.    Water is a molecule; therefore it can dissolve other molecular solutes only.

Which of the following correctly defines spectator ions?
A.    Ions that combine to form an insoluble precipitate.
B.    Ions that do not participate in the reaction although they are present.
C.    Ions that appear in a net ionic equations.
D.    Ions that are dissociated in solutions.

Select the correct net ionic equation of the total ionic equation is given by
2K⁺ (aq) + 2Cl^- (aq) + Pb²⁺ (aq) + 2CH₃COO^- (aq) → 2K⁺ (aq) + PbCl₂ (s) + 2CH₃COO^- (aq)
1.   K⁺ (aq) + Cl^- (aq) → KCl (s)
2.   K⁺ (aq) + CH₃COO^- (aq) → KCH₃COO (s)
3.   K⁺ (aq) + CH₃COO (aq) → K⁺ (aq) + CH₃COO^- (aq)
4.   Pb²⁺ (aq) + 2Cl^- (aq) → PbCl₂ (s)

A chemical equation that shows all reactants and products as intact, undissociated compounds is called a(n)           equation.  The name is misleading because not all compounds are composed of           .

Identify ALL the spectator ions in the total ionic equation
2Na⁺ (aq) + SO₄^2- (aq) + Ba²⁺ (aq) + 2Cl^- (aq) → BaSO₄ (s) + 2Na⁺ (aq) + 2Cl^- (aq)
A.   Cl^-
B.   Na⁺
C.   Ba⁺
D.   2Na⁺
E.   SO₄^2-

Which of the following statements correctly describes a net ionic equation?  Select all that apply.
A.   A net ionic equation consists of the formulas for the spectator ions.
B.   A net ionic equation shows only the ionic species that are involved in the reaction and the products that form.
C.   A net ionic equation shows only the chemical changes that is taking place in a reaction.
D.   A net ionic equation shows only the species that have undergone a change in the reaction, and any products that form.
E.   All species are represented as ions in this type of equation.

An ionic compound will dissolve when the attraction between the        molecules and the ions is greater than the attraction between the          themselves.

When ions are tightly surrounded by solvent molecules they are said to be           .
A.    precipitated
B.    separated
C.    solvated
D.    saturated

The H⁺ ions produced by an acid in aqueous solution associate strongly with H₂O to form the        ion, which has the formula          .
A.    hydronium, OH^-
B.    hydronium, H₃O⁺
C.    hydronium, H₃O⁺
D.    protonium, H^-

An acid is a covalently bonded substance that nonetheless produces         when dissolved in water.   This occurs because the acid molecules contains a(n)          covalent bond between H and another atom X (such as the bond in H-Cl).  The H of the acid is strongly attracted to the partially negative O atom of water.  The H-X bond in the acid breaks and the acid            .

Which of the following compounds are acids?  Select all that apply.
A.   NaOH
B.   CaCO₃
C.   H₃PO₄
D.   CH₃CH₂COOH
E.   HBr

Match each ion to the correct description of its solubility when combined with an ion of opposite charge.
A.   soluble except with Ca⁺, Sr²⁺, Ba²⁺, Ag⁺, and Pb²⁺
B.   soluble in all combinations
C.   soluble except with Ag⁺, Pb²⁺, Cu⁺, and Hg²⁺
D.   insoluble except with Group 1A cations or NH₂⁺
1.   Cl^-
2.   Na⁺
3.   CO₃^2-
4.   SO₄^2-

The H⁺ ions produced by an acid in an aqueous solution associate strongly with H₂O to form the _____ ion, which has the formula ______.
A.    protonium, H^-
B.    hydronium, OH^-
C.    hydronium, H₃O⁺
D.    hydronium, H₃O⁺

An acid is a covalently bonded substance that nonetheless produces ______ when dissolved in water.  This occurs because the acid molecule contains a(n) ______ covalent bond between H and another atom X (such as the bond in H-Cl).  The H of the acid is strongly attracted to the partially negative O atom in water.  The H-X bond in the acid breaks and the acid ______.

Which of the following compounds are acids?  Select all that apply.
A.   NaOH
B.   CaCO₃
C.   H₃PO₄
D.   CH₃CH₂COOH
E.   HBr

Match each ion with the correct description of its solubility when combined with an ion with opposite charge.
A.   Cl^-
B.   Na⁺
C.   CO₃^2-
D.   SO₄^2-
1.   soluble except with Ca²⁺, Sr²⁺, Ba²⁺, Ag⁺, and Pb²⁺
2.   soluble in all combinations
3.   soluble expect with Ag⁺, Pb²⁺, Cu⁺, and Hg₂²⁺
4.   insoluble except with Group 1A cations or NH₄⁺

Which of the following correctly defines a precipitate?
A.    An aqueous solution that forms from a solid
B.    A liquid that forms in a reaction
C.    A solid product that separates from a solution
D.    A soluble ionic compound

A neutralization reaction occurs between a(n) _____ and a(n) ______.

When a strong acid reacts with a strong base, the products are typically a(n) _____ compound, which is called a(n) ______, and the neutral molecular ______.

Which of the following options correctly describes a precipitation reaction?  Select all that apply.
A.    The reactants are insoluble precipitates.
B.    This type of reaction forms one or more insoluble products
C.    This type of reaction usually involves ionic compound
D.    This type of reaction often occurs in aqueous solution
E.    The reaction involves a transfer of electrons between reactants