Integrated Physical Science chapter 9 & 10

The element sodium (Na) has how many valence electrons?

1

A solute is

b. the material that dissolves in the solvent portion of a solution. Correct

A chemical equation is balanced by changing (the)

coefficients

A polar molecule has a positive and a negative side or end.

TRUE

The solubility of a gas in water decreases as the water temperature increases.

TRUE

Water containing large amounts of Mg2+ and Ca2+ ions is said to be hard because it is hard to make soap lather in the water.

TRUE

List 3 materials (not chemical compounds!) that contain hydrogen bonds.

The correct answer is: proteins, DNA, spiderwebs, cellulose, water, nylon

What effect does temperature have on Reaction Rates?

a. Higher temperatures tend to increase reaction rates. Correctcorrect

Why is the salinity of seawater increased when it freezes?

a. The ice that is formed is essentially pure water so there is less water in solution. Correctcorrect answer

Hydrogen and oxygen are combined to form water. What term best describes this process?

a. chemical change Correctcorrect

What type of reaction has the general form AX + BY → AY + BX.

a. ion exchange Correctcorrect answer

If the force of attraction between the ions in a solid is very strong, you would expect the solid to have

a. low solubility in water. Correct

The outer electrons of metal atoms differ from the outer electrons of nonmetal atoms in that the outer electrons of metals

all of above

Why does ice, the solid form of water, float?

b. It floats because it is less dense than water because of the open spaces between molecules produced by its hexagonal structure.

According to the definition of acids and bases, NH3 is

b. a base because it can accept H+ ions from water.

The heat of fusion, specific heat, and heat of vaporization of water are high compared to similar substances such as hydrogen sulfide, H2S, because

b. hydrogen bonds form between water molecules. Correct

Metallic bonds create materials with properties that make them

b. malleable and good conductors of electricity. Correctcorrect

To say a chemical equation is balanced means the

b. number of times each element appears as a reactant is equal to the number of times it appears as a product

The terms 'ionic, covalent, and metallic' represent

b. three ways atoms in a molecule can have relationships with their electrons. Correctcorrect

Which of the following are properties of basic solutions?

c. They feel slippery. Correct

To see an everyday example of oxidation-reduction, you might observe

c. a car rusting. Correctcorrect

A hydrogen bond is

c. a force between the hydrogen atom of one polar molecule and another polar molecule. Correct

A solution has a pH of 9. This means that the solution is

c. basic. Correct

Which of the following terms best describes a well mixed cup of coffee with sugar?

c. homogeneous mixture Correctcorrect

Chemical energy is stored within molecules as

c. internal potential energy. Correctcorrect

Covalent bonds and ionic bonds differ in that

c. ionic bonds don't involve the sharing of electrons Correctcorrect

Chemical bonds are

c. the redistribution of electrons between atoms, leading to a more stable configuration. Correctcorrect

The electrons in the outer level of the atom are called

c. valence electrons. Correctcorrect

in liquid solutions, the solute is

d all of these could be true

Select the best description of an element.

d. A pure substance that cannot be broken down into anything simpler by chemical or physical means. Correctcorrect

Which of the following are properties of acidic solutions?

d. All of these are true. Correct

What elements tend to form ionic compounds?

d. Elements found on opposite sides of the periodic table.

What is the difference between a compound and a mixture?

d. The components of a mixture are not chemically bonded together Correctcorrect

Hydrogen bonding in water accounts for

d. all of these are true. Correct

Covalent bonds are formed when

d. atoms share electrons. Correctcorrect

A solution with a pH of 2

d. is one tenth as acidic as a solution with a pH of 1.

Which makes the best electrical conductor?

d. metallic bonds. Correctcorrect

Acid rain

d. occurs when nitrogen oxides undergo gas-phase reactions producing nitric acid.

The modern definition of an acid is any substance

d. that is a proton donor. Correctcorrect answer

Which statement is true of oxidation-reduction reactions?

e. All of the above are true. Correctcorrect

Water solutions of ionic substances that conduct electricity are called

electrolytes

Salt is spread on icy roads because it

lowers the freezing point of water.

What is a particle composed of two or more atoms held together by an attractive force called?

molecule

Air is considered to be a homogeneous mixture that is 79% nitrogen gas, 20% oxygen gas and 1% all the other gases. In this mixture, nitrogen can be considered

solvent

The presence of solute molecules makes a solution freeze at a lower temperature than the pure solvent.

true