Chemistry Exam

Solution A, solution B, and the mixture are all yellow.

You mix solution A with solution B in a beaker. Which of the following observations does not help you prove that a chemical reaction has occurred?

molar enthalpy of fusion

how much energy is needed to melt one mole of a substance

diffusion

spontaneous mixing of two substances caused by their random motion

evaporation

the change of state from a liquid to a gas

freezing

the change of state in which a liquid becomes a solid as heat is removed

melting

the change of state in which a solid becomes a liquid by adding heat or changing pressure

mol

the expression mass x 1 mol/molar mass has the unit

When the formula equation Fe3O4 + Al -> Al2O3 + Fe is correctly balanced the coefficient of Fe is number

9

decomposition

Calcium carbonate, CaCO3, reacts to form calcium oxide, CaO, and carbon dioxide, CO2. What type of reaction is this?

the reactant is given in moles and the product is sought in moles.

Fewer steps are required to solve stoichiometry problems when

108 g

For the reaction represented by the equation 2H2 + O2 ® 2H2O, how many grams of water are produced from 6.00 mol of hydrogen?

9

For the reaction represented by the equation N2 + 3H2 mc001-1.jpg 2NH3, how many moles of nitrogen are required to produce 18 mol of ammonia?

All of the above

From a complete and correctly written chemical equation, you can obtain the

O2

How would oxygen be represented in the formula equation for the reaction of methane and oxygen to yield carbon dioxide and water?

the particles move faster in a gas and there is a greater distance between them

If a gas and a liquid are at the same temperature and pressure, diffusion occurs much faster in the gas because

calculate the mass of the product produced from a known mass of reactant.

If one knows the mole ratio of a reactant and product in a chemical reaction, one can

liquid

If the particles in a sample of matter are attracted to each other but can move past each other easily, the matter is a

dissolved in water

In a chemical equation, the symbol (aq) indicates that the substance is

double-displacement reaction.

In a reaction, the ions of two compounds exchange places in aqueous solution to form two new compounds. This reaction is called a

4:3

In the equation 2Al2O3 -> 4Al + 3O2, what is the mole ratio of aluminum to oxygen?

1:1

In the equation 6CO2 + 6H2O -> C6H12O6 + 6O2, the mole ratio of water to oxygen is

3:2

In the equation Al2(SO4)3 + 3Ca(OH)2 -> 3CaSO4 + 2Al(OH)3, the mole ratio of calcium hydroxide to aluminum hydroxide is

a coefficient and a subscript

In the expression 3CO2, the numbers 3 and 2 are, respectively,

In the reaction described by the word equation sodium + water mc011-1.jpg sodium hydroxide + hydrogen gas

In the reaction described by the word equation sodium + water mc011-1.jpg sodium hydroxide + hydrogen gas

2:1

In the reaction represented by the equation C + 2H2 ® CH4, what is the mole ratio of hydrogen to methane?

mass of water produced

In the reaction represented by the equation CH4(g) + 2O2(g) mc010-1.jpg CO2(g) + 2H2O(g), a mass of 125 g CH4 is reacted with excess oxygen. The expression is used to calculate the (will have long equation in it)

1:2

In the reaction represented by the equation N2 + 3H2 -> 2NH3, what is the mole ratio of nitrogen to ammonia?

synthesis reaction

In what kind of reaction do two or more substances combine to form a new compound?

synthesis

In which type of reaction do two or more compounds react to form one product?

H2

In writing a chemical equation that produces hydrogen gas, the correct representation of hydrogen gas is

closer arrangement

Liquids and solids are much denser than gases because the particles of liquids and solids have a

the attractive forces between particles restrict their movement.

Liquids diffuse more slowly than gases because

triple point

On a phase diagram, the point at which all equilibrium lines join is the

enthalpy of vaporization

One mole of benzene vapor condenses at its boiling point. The amount of energy released by the benzene as it completely condenses is known as its molar

2.1 g O3

Ozone, O3, is produced in automobile exhaust by the reaction represented by the equation NO2(g) + O2(g) mc006-1.jpg NO(g) + O3(g) What mass of ozone is predicted to form from the reaction of 2.0 g NO2 in a car's exhaust and excess oxygen

force/area

Pressure =

solid to a gas

Sublimation involves changing from a

indicate the number of moles of each substance that react.

The coefficients in a chemical equation

relative numbers of moles of reactants and products

The coefficients in a chemical equation represent the

less than that of a gas

The compressibility of a liquid is generally

(s)

The formation of a solid product in a chemical reaction is represented by the symbol

volume

The kinetic-molecular theory of gases assumes that the particles of an ideal gas are separated by great distances. This implies that the gas particles are considered to have no definite

grams

The most steps are required to solve stoichiometry problems when the reactant is given in grams and the product is sought in

vibrational

The movements of particles in solids can best be described as

coefficients in the balanced equation

The ratios of the volumes of the gaseous reactants and products in a chemical reaction at constant temperature and pressure can be determined from the

decomposition reaction.

The reaction represented by the equation 2HgO(s) ® 2Hg(l) + O2(g) is a(n)

decomposition reaction

The reaction represented by the equation 2KClO3(s) ® 2KCl(s) + 3O2(g) is a(n)

double-displacement reaction

The reaction represented by the equation Pb(NO3)2(aq) + 2KI(aq) ® PbI2(s) + 2KNO3(aq) is a

coefficients

To balance a chemical equation, it is permissible to adjust the

coefficients

To balance a chemical equation, it may be necessary to adjust the

adjust the coefficients

To balance a chemical equation, you must

low pressure and high temperature

Under which conditions does a real gas behave very much like an ideal gas?

hydrogen bonding

Water has an unusually high molar enthalpy of vaporization because of its

Rubbing alcohol will vaporize faster.

What is likely to happen to a liquid mixture of water and rubbing alcohol in an open flask as temperature is increased while pressure stays the same?

2Al + 3CuSO4 ® Al2(SO4)3 + 3Cu

What is the balanced equation when aluminum reacts with copper(II) sulfate?

3 to 2

What is the mole ratio of H2O to H3PO4 in the following chemical equation? P4O10 6H2O -> 4H3PO4

4

What is the total number of molecules that is represented by the following chemical equation? NH4NO2 mc010-1.jpg N2 2H2O Select one:

single-displacement

What type of chemical reaction does the following chemical equation represent? 2HCl(aq) + Cr(s) mc007-1.jpg H2(g)+ CrCl2(aq)

synthesis

What type of chemical reaction is represented by the following word equation? iron + oxygen mc006-1.jpg iron(II) oxide

carbon dioxide

When heated, a metal carbonate decomposes into a metal oxide and

exhibit a sharply defined melting temperature

When heated, a pure crystalline solid will

9

When the equation Fe3O4 + Al ® Al2O3 + Fe is correctly balanced, what is the coefficient of Fe?

decreases

When there is a small decrease in temperature, the average kinetic energy of the particles of a liquid

stoichiometry

Which branch of chemistry deals with the mass relationships of elements in compounds and the mass relationships among reactants and products in chemical reactions?

particle mobility

Which characteristic accounts for the fluidity of gases and liquids?

1,1,2

Which coefficients correctly balance the formula NH4NO2 -> N2 + H20

1,1,2

Which coefficients correctly balance the formula equation NH4NO2(s)® N2(g) + H2O(l)

1, 1, 1

Which coefficients correctly balance the formula equation CaO + H2O ® Ca(OH)2?

2,2,3

Which coefficients correctly balance the formula equation below? KClO3(s) mc008-1.jpg KCl(s) + O2(g)

KCl + Br2 mc013-2.jpg KBr Cl2

Which equation below violates the law of conservation of mass?

2H2 + O2 + H20

Which equation is not balanced?

2H2 + O2 mc020-4.jpg H2O

Which equation is not balanced?

Volume vs Pressure for a Gas at constant temperature

Which graph illustrates Boyle's law?

high kinetic energy

Which of the following causes particles in a liquid to escape into a gas state?

4Fe 3O2 mc022-3.jpg 2Fe2O3

Which of the following equations represents the balanced equation for the reaction of iron and oxygen?

The numbers of atoms of each element are the same on both sides of the equation.

Which of the following indicates that a chemical equation is balanced?

One element replaces another in a compound.

Which of the following is true regarding single-displacement reactions?

the amount of energy required to break the ionic bonds in calcium fluoride

Which of the following would not be studied in the branch of chemistry called stoichiometry?

evaporation

Which term best describes the process by which particles escape from the surface of a nonboiling liquid and enter the gas state?

mole ratio of any two substances in the reaction

A balanced chemical equation allows one to determine the

same number of each kind of atom appears in the reactants and in the products

A chemical equation is balanced when the

1.34 atm

A sample of helium gas has a volume of 250.0 mL when its pressure is 0.935 atm. If the temperature remains constant, what will the pressure of the gas be when it has a volume of 175.0 mL?

always equal to the total mass of the products

According to the law of conservation of mass, the total mass of the reacting substances is

random arrangement

Amorphous solids behave like liquids at certain temperatures because of their