Chem Part 3

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

In nuclear reactors, the role of control rods is to a. accelerate neutrons. b. absorb neutrons. c. slow down neutrons. d. absorb energy.

B

In the word equation, sodium oxide + water sodium hydroxide, the formula for sodium hydroxide is represented by a. Na2OH. b. NaOH. c. NaO2. d. Na2O.

B

In what kind of reaction do the ions of two compounds exchange places in aqueous solution to form two new compounds? a. synthesis reaction b. double-displacement reaction c. decomposition reaction d. combustion reaction

B

What does the 101 in represent? a. the mass number b. the atomic number c. the nuclide number d. the number of neutrons

B

What is the oxidation number of oxygen in most compounds? a. -8 b. -2 c. 0 d. +1

B

When the equation Fe3O4 + Al Al2O3 + Fe is correctly balanced, what is the coefficient of Fe? a. 3 b. 4 c. 6 d. 9

C

When the equation Fe3O4 + Al Al2O3 + Fe is correctly balanced, what is the coefficient of Fe? a. 3 b. 4 c. 6 d. 9

D

In a chemical reaction a. the mass of the reactants equals the mass of the products. b. the mass of the products is greater than the mass of reactants. c. the number of atoms in the reactants and products must change. d. energy as heat must be added to the reactants.

A

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

Predict the product of the reaction represented by the following equation: MgO + CO2 a. MgCO3 b. Mg + CO3 c. MgC + O3 d. MgCO2 + O

A

The decomposition of a substance by an electric current is called a. electrolysis. b. conduction. c. ionization. d. transformation.

A

The half-life of an isotope is the time required for half the nuclei in a sample to a. undergo radioactive decay. c. undergo nuclear fusion. b. undergo nuclear fission. d. react chemically.

A

The reaction represented by the equation 2Mg(s) + O2(g) 2MgO(s) is a a. synthesis reaction. b. decomposition reaction. c. single-displacement reaction. d. double-displacement reaction

A

The reaction represented by the equation Pb(NO3)2(aq) + 2KI(aq) PbI2(s) + 2KNO3(aq) is a a. double-displacement reaction. b. synthesis reaction. c. decomposition reaction. d. combustion reaction.

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 does the 218 in polonium-218 represent? a. the mass number b. the atomic number c. the mass defect d. the neutron number

A

What does the 4 in represent? a. the mass number b. the atomic number c. the number of protons d. the number of neutrons

A

What is the half-life of an isotope if 125 g of a 500 g sample of the isotope remain after 3.0 years? a. 1.5 years b. 2.5 years c. 3.5 years d. 4.5 years

A

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

The equation AX A + X is the general equation for a a. synthesis reaction. b. decomposition reaction. c. combustion reaction. d. single-displacement reaction.

B

The reaction of calcium oxide, CaO, with water yields a. calcium and oxygen gas. b. calcium hydroxide. c. calcium and a salt. d. carbon dioxide and water.

B

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

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 device uses controlled nuclear fission to produce new radioactive substances and energy? a. synchrotron b. nuclear reactor c. nuclear bomb d. linear accelerator

B

What is the balanced equation for the combustion of sulfur? a. S(s) + O2(g) SO(g) b. S(s) + O2(g) SO2(g) c. 2S(s) + 3O2(g) SO3(s) d. S(s) + 2O2(g) SO42-(aq)

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(s) N2(g) + H2O(l)? a. 1, 2, 2 b. 1, 1, 2 c. 2, 1, 1 d. 2, 2, 2

B

Which of the following is a formula equation for the formation of carbon dioxide from carbon and oxygen? a. Carbon plus oxygen yields carbon dioxide. b. C + O2 -- CO2 c. CO2 -- C + O2 d. 2C + O -- CO2

B

Which statement is true about half-lives? a. Different atoms of the same nuclide have different half-lives. b. Each radioactive isotope has its own half-life. c. All radioactive nuclides of an element have the same half-life. d. All radioactive nuclides have the same half-life.

B

Which word equation represents the reaction that produces water from hydrogen and oxygen? a. Water is produced from hydrogen and oxygen. b. Hydrogen plus oxygen yields water. c. H2 + O2 -- water. d. Water can be separated into hydrogen and oxygen.

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

In one type of synthesis reaction, an element combines with oxygen to yield a(n) a. acid. b. hydroxide. c. oxide. d. metal.

C

In writing a chemical equation that produces hydrogen gas, the correct representation of hydrogen gas is a. H. b. 2H. c. H2. d. OH.

C

Magnesium hydroxide decomposes to yield magnesium oxide and a. hydrogen. b. oxygen. c. water. d. salt.

C

The complete balanced equation for the reaction between zinc hydroxide and acetic acid is a. ZnOH + CH3COOH ZnCH3COO + H2O. b. Zn(OH)2 + CH3COOH Zn + 2CO2 +3H2O. c. Zn(OH)2 + 2CH3COOH Zn(CH3COO)2 + 2H2O. d. Zn(OH)2 + 2CH3COOH Zn(CH3COO)2 + H2 + O2.

C

The equation A + BX AX + B is the general equation for a a. double-displacement reaction. b. decomposition reaction. c. single-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 represented by the equation Cl2(g) + 2KBr(aq) 2KCl(aq) + Br2(l) is a(n) a. synthesis reaction. b. decomposition reaction. c. single-displacement reaction. d. combustion reaction.

C

The reaction represented by the equation Mg(s) + 2HCl(aq) H2(g) + MgCl2(aq) is a a. composition reaction. b. decomposition reaction. c. single-displacement reaction. d. double-displacement reaction

C

Which of the following is a fission reaction? a. hydrogen-2 and hydrogen-3 combining to form a helium-4 atom and a neutron b. carbon-12 and hydrogen-1 combining to form a nitrogen-13 atom c. uranium-235 absorbing a neutron and breaking into barium-141, krypton-92, and three neutrons d. a glucose molecule being metabolized with oxygen to form carbon dioxide and water

C

According to the law of conservation of mass, the total mass of the reacting substances is a. always more than the total mass of the products. b. always less than the total mass of the products. c. sometimes more and sometimes less than the total mass of the products. d. always equal to the total mass of the products

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

Magnesium bromide (aq) + chlorine (g) yields a. Mg(s) and BrCl(aq). b. MgCl(aq) and Br2(l). c. MgBrCl(aq). d. MgCl2(aq) and Br2(l).

D

Reactions that affect the nucleus of an atom are called a. fusions. b. fissions. c. radioactive decays. d. nuclear reactions.

D

The equation AX + BY AY + BX is the general equation for a a. synthesis reaction. b. decomposition reaction. c. single-displacement reaction. d. double-displacement reaction.

D

The reaction represented by the equation 2HgO(s) 2Hg(l) + O2(g) is a(n) a. single-displacement reaction. b. synthesis reaction. c. combustion reaction. d. decomposition reaction.

D

What is the small whole number that appears in front of a formula in a chemical equation? a. a subscript b. a superscript c. a ratio d. a coefficient

D

When sodium chlorate, NaClO3, decomposes, the products are a. sodium hydroxide and water. b. sodium oxide and chlorine. c. sodium and chlorine oxide. d. sodium chloride and oxygen.

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 of the following is a fusion reaction? a. uranium-235 absorbing a neutron and splitting into xenon-140, strontium-94, and two neutrons b. hydrochloric acid combining with sodium hydroxide to form NaCl and water c. carbon-14 decaying into nitrogen-14 and a beta particle d. curium-246 combining with carbon-12 to form nobelium-254 and four neutrons

D