ch8

After the first steps in writing an equation, the equation is balanced by a. adjusting subscripts to the formula(s). b. adjusting coefficients to the smallest whole-number ratio. c. changing the products formed. d. making the number of reactants equal to the number of products.

B

An element in the activity series can replace any element a. in the periodic table. b. below it on the list. c. above it on the list. d. in its group.

B

The reaction 2KClO3(s) → 2KCl(s) + 3O2(g) is a(n) a. synthesis reaction. b. decomposition reaction. c. combustion reaction. d. ionic reaction.

B

The reaction, C2H5OH + 3O2 ⎯⎯heat ⎯→ 2CO2 + 3H2O, will occur most rapidly if a. C2H5OH is a liquid and O2 is a liquid. b. C2H5OH and O2 are in close contact. c. CO2 is a gas and H2O is a liquid. d. CO2 is a gas and H2O is a gas.

B

The word equation for the formula equation shown is C2H5OH + O2 → CO2 + H2O + energy a. carbon dioxide + water → ethanol + oxygen + energy. b. ethanol + oxygen → carbon dioxide + water + energy. c. ethanol + oxygen + energy → carbon dioxide + water. d. ethanol + oxygen + energy → carbon dioxide + water + energy.

B

The word equation solid carbon + oxygen gas → carbon dioxide gas + energy, represents a chemical reaction because a. the reaction releases energy. b. CO2 has chemical properties that differ from those of C and O. c. the reaction absorbs energy. d. CO2 is a gas and carbon is a crystal

B

What is the balanced equation when aluminum reacts with copper(II) sulfate? a. Al + Cu2S → Al2S + Cu b. 2Al + 3CuSO4 → Al2(SO4)3 + 3Cu c. Al + CuSO4 → AlSO4 + Cu d. 2Al + Cu2SO4 → Al2SO4 + 2Cu

B

Which coefficients correctly balance the formula equation NH4NO2 → N2 + H2O? a. 1, 2, 2 b. 1, 1, 2 c. 2, 1, 1 d. 2, 2, 2

B

How would oxygen be represented in the formula equation for the reaction of methane and oxygen to yield carbon dioxide and water? a. oxygen b. O c. O2 d. O3

C

If metal X is lower than metal Y in the activity series, then metal X a. replaces ions of metal Y in a solution. b. is more active than metal Y. c. is less active than metal Y. d. forms positive ions more readily than does metal Y.

C

In the unbalanced formula equation CO + O2 → CO2 + energy, energy a. is absorbed. b. can be considered a reactant. c. is released. d. Both (a) and (b)

C

The equation A + BX → AX + B is the general equation for a a. double-displacement reaction. b. decomposition reaction. c. displacement reaction. d. combustion reaction.

C

The equation A + X → AX is the general equation for a(n) a. combustion reaction. b. ionic reaction. c. synthesis reaction. d. double-displacement reaction

C

The reaction Cl2(g) + 2KBr(aq) → 2KCl(aq) + Br2(l) is a(n) a. synthesis reaction. b. ionic reaction. c. displacement reaction. d. combustion reaction.

C

The state of matter for a reactant or a product in a chemical equation is indicated by a a. coefficient before the formula. b. subscript after the formula. c. symbol after the formula. d. superscript after the formula

C

What is the name of a list of elements arranged according to the ease with which they undergo certain chemical reactions? a. reactivity list b. reaction sequence c. activity series d. periodic list

C

Which coefficients correctly balance the formula equation Zn(OH)2 + CH3COOH → Zn(CH3COO)2 + H2O? a. 1, 2, 1, 1 b. 2, 1, 2, 1 c. 1, 2, 1, 2 d. 2, 1, 1, 2

C

When the formula equation Zn(OH)2 + CH3COOH → Zn(CH3COO)2 + H2O is correctly balanced, the coefficient of Zn(CH3COO)2 is ____________________.

1

When the formula equation H2(g) + Cl2(g) → HCl(g) is correctly balanced, the coefficient of HCl is ____________________.

2

When the formula equation CuSO4(aq) + Fe(s) → Fe2(SO4)3(aq) + Cu(s) is correctly balanced, the coefficient of CuSO4(aq) is ____________________.

3

When the formula equation Fe3O4 + Al → Al2O3 + Fe is correctly balanced, the coefficient of Fe is ____________________.

9

An insoluble solid produced by a chemical reaction in solution is called a. a precipitate. b. a reactant. c. a molecule. d. the mass of the product.

A

In what kind of reaction does a single compound produce two or more simpler substances? a. decomposition reaction b. synthesis reaction c. displacement reaction d. ionic reaction

A

In what kind of reaction does one element replace a similar element in a compound? a. displacement reaction b. combustion c. decomposition reaction d. ionic reaction

A

The products of the reaction, C2H5OH + 3O2 → 2CO2 + 3H2O have the same _____ as the reactants. a. atoms. b. coefficients. c. molecules. d. subscripts.

A

To balance a chemical equation, it may be necessary to adjust the a. coefficients. b. subscripts. c. formulas of the products. d. number of products.

A

What can be predicted by using an activity series? a. whether a certain chemical reaction will occur b. the amount of energy released by a chemical reaction c. the electronegativity values of elements d. the melting points of elements

A

Which coefficients correctly balance the formula equation CaCO3(s) → CaO(s) + CO2(g)? a. 1, 1, 1 b. 1, 3, 1 c. 2, 6, 3 d. 3, 1, 2

A

In the chemical equation 2AlCl3(aq) + 3Pb(NO3)2(aq) → 3PbCl2(s) + 2Al(NO3)2(aq), the spectator ions are ____________________ and ____________________.

Al 3+ No-3

A chemical equation is balanced when the a. coefficients of the reactants equal the coefficients of the products. b. same number of each kind of atom appears in the reactants and in the products. c. products and reactants are the same chemicals. d. subscripts of the reactants equal the subscripts of the products.

B

A precipitate forms in a double-displacement reaction when a. hydrogen gas reacts with a metal. b. positive ions combine with negative ions. c. water boils out of the solution. d. a gas escapes.

B

A reaction of a hydrocarbon, in which carbon dioxide and water are produced, is classified as a a. decomposition reaction. b. combustion reaction. c. double-displacement reaction. d. synthesis reaction.

B

After the correct formula for a reactant in an equation has been written, the a. subscripts are adjusted to balance the equation. b. formula should not be changed. c. same formula must appear as the product. d. symbols in the formula must not appear on the product side of the equation.

B

Knowledge about what products are produced in a chemical reaction is obtained by a. inspecting the chemical equation. b. balancing the chemical equation. c. laboratory analysis. d. writing a word equation

c

The equation AX → A + X is the general equation for a(n) ____________________ reaction

decomposition

The reaction 2HgO(s) → 2Hg(l) + O2(g) is classified as a(n) ____________________ reaction.

decomposition

The reaction Mg(s) + 2HCl(aq) → H2(g) + MgCl2(aq) is classified as a(n) ____________________ reaction.

displacement

In a(n) _________________________ reaction, ions of two compounds exchange places in aqueous solution to form new compounds.

double displacement

The equation AX + BY → AY + BX is the general equation for a(n) _________________________ reaction.

double displacement

When balancing a chemical equation, insert coefficients to make the number of atoms of each of the ____________________ in the products equal to that of the reactants.

elements

When placed in water, a metal more active than hydrogen will form two substances, a metal hydroxide and ____________________ gas.

hydrogen

A solid produced by a chemical reaction that then separates from the solution is called a(n) ____________________.

precipitate

A chemical reaction has NOT occurred if the products have a. the same mass as the reactants. b. more energy than the reactants. c. less energy than the reactants. d. the same chemical properties as the reactants

D

In what kind of reaction do two or more substances combine to form a new compound? a. decomposition reaction b. ionic reaction c. double-displacement reaction d. synthesis reaction

D

Which coefficients correctly balance the formula equation CaO + H2O → Ca(OH)2? a. 2, 1, 2 b. 1, 2, 3 c. 1, 2, 1 d. 1, 1, 1

D

Which equation is NOT balanced? a. 2H2 + O2 → 2H2O b. 4H2 + 2O2 → 4H2O c. H2 + H2 + O2 → H2O + H2O d. 2H2 + O2 → H2O

D

Which observation does NOT indicate that a chemical reaction has occurred? a. formation of a precipitate b. production of a gas c. evolution of energy d. change in total mass of substances

D

In writing a formula equation for a reaction that produces hydrogen gas, the correct representation of hydrogen gas is ____________________.

H2 (g)

In an equation, the symbol for a substance in water solution is ____________________

aq

The mass of the products of the reaction C2H5OH + 3O2 → 2CO2 + 3H2O equals the mass of the reactants because the products are made up of the same ____________________ as the reactants.

atoms

A catalyst for a reaction is indicated by a ____________________ written over the arrow in a chemical equation

chemical formula

The small whole number that appears in front of a formula in a chemical equation is called a(n) ____________________.

coefficient

In the chemical reaction 2Cr(s) + 3O2(g) → 2CrO3(s), two chromium atoms combine with ____________________ oxygen atoms

six

In the chemical equation 2AlCl3(aq) + 3Pb(NO3)2 (aq) → 3PbCl2(s) + 2Al(NO3)3(aq), the state of PbCl2 is a(n) ____________________.

solid

Ions that are present in solution in which a reaction is taking place but that do not participate in the reaction are called ____________________.

spectator ions

The reaction 2Mg(s) + O2(g) → 2MgO(s) is classified as a(n) ____________________ reaction.

synthesis