Practice Exam Answers

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At what temperature is the substance a heated gas?

at 100 times degree C

above 100 times degree C

below 0 times degree C

between 0 times degree C and 100 times degree C

A compound accepts electrons from another substance to form a covalent bond. Which term best describes this compound’s behavior?

Bronsted-Lowry acid

Bronsted-Lowry base

Arrhenius base

Lewis acid

The alpha decay of a radioactive nuclide (X) emits a He- 4 nucleus and produces an isotope of 92235U What is X ?

92 to the 236th power cap u

91 to the 235th power Pa

93 to the 235th power Np

94 to the 239th power Pu

Brownian motion is not observed in a mixture that includes two phases. Which best identifies the mixture?

a solution

a colloid

a suspension

an alloy

Consider the reaction. 3 cap o sub 2 g long left right arrow 2 cap o sub 3 g At 298 cap k , the equilibrium concentration of cap o sub 2 is 1 point 6 times 10 to the negative 2 power cap m , and the equilibrium concentration of cap o sub 3 is 2 point 8 6 times 10 to the negative 28 power cap m What is the equilibrium constant of the reaction at this temperature?

2 point 0 times 10 to the negative 50 power

2 point 0 times 10 to the 50th power

1 point 8 times 10 to the negative 26 power

1 point 8 times 10 to the 26th power

A plasma that has particles that never collide frequently enough to exchange kinetic energy and never reach a temperature equal to the surroundings is categorized as a

ionized plasma.

low density plasma.

thermal plasma.

nonthermal plasma.

Which compound contains a triple bond?

Image with description A C is connected to an O with 2 parallel vertical lines, and below left to H with a single line and below right to O H with a single line.

Image with description 2 C's are connected by 3 parallel lines. There is an H connected with a single line to the left and to the right.

Image with description 2 C's are connected with 2 parallel lines. There are H's connected with single lines above left, above right, below right, and below left of the 2 C's.

Image with description 2 C's are connected with a single line, and each has an H attached by a single line above, below, and outside.

How do aromatic hydrocarbons differ from alkenes?

Aromatic hydrocarbons are unsaturated, and alkenes are saturated.

Alkenes are saturated, and aromatic hydrocarbons are unsaturated.

Aromatic hydrocarbons are flat, geometric molecules, and alkenes are not.

Alkenes are flat, planar molecules, and aromatic hydrocarbons are not.

Which best describes the reducing agent in this reaction? Cl sub 2 times A q plus 2 Br raised to the negative A q power rightarrow 2 Cl raised to the negative A q power plus Br sub 2 times A q

Bromine Br loses an electron, so it is the reducing agent.

Chlorine Cl loses an electron, so it is the reducing agent.

Bromine Br gains an electron, so it is the reducing agent.

Chlorine Cl gains an electron, so it is the reducing agent.

How does an increase in reactant concentration affect the rate of reaction?

It leads to less frequent collisions, which decrease reaction rate.

It leads to less frequent collisions, which increase reaction rate.

It leads to more frequent collisions, which decrease reaction rate.

It leads to more frequent collisions, which increase reaction rate.

Widespread use of fuel cell vehicles poses a danger because

fuel cells emit a greenhouse gas that endangers the ecosystem.

it is difficult to safely transport and store hydrogen gas before it is used.

hydrogen used to power fuel cells could run out and disappear from Earth.

it is hard to build fuel cell vehicles that travel slowly enough to match speed limits.

Consider this chemical equation. Mg OH sub 2 plus 2 HNO sub 3 rightarrow Mg open paren NO sub 3 close paren sub 2 plus 2 cap h sub 2 cap o Which is the net ionic equation?

Mg raised to the 2 plus power plus 2 NO sub 3 raised to the negative right arrow Mg raised to the 2 plus power plus 2 NO sub 3 raised to the negative power power

Mg raised to the 2 plus power plus 2 OH raised to the negative plus 2 power cap h raised to the plus right arrow Mg raised to the 2 plus power 2 cap h sub 2 cap o power

cap h raised to the plus plus OH raised to the negative right arrow cap h sub 2 cap o power power

Mg raised to the 2 plus power plus 2 OH raised to the negative plus 2 power cap h raised to the plus plus 2 power NO sub 3 raised to the negative right arrow Mg raised to the 2 plus power plus 2 NO sub 3 raised to the negative plus 2 power cap h sub 2 cap o power

After a radioactive atom decays, it is the same element that it was before with no measurable change in mass. Which kind of decay has occurred, and how do you know?

alpha decay because it creates a new isotope of the same element

gamma decay because photons have no mass

beta decay because this kind of decay cannot change one element into another

alpha decay because alpha particles have no mass

A sample contains 25 percent parent isotope and 75 percent daughter isotopes. If the half-life of the parent isotope is 72 years, how old is the sample?

360 years old

144 years old

288 years old

216 years old

Which of these is an example of a physical change?

sodium, when exposed to chlorine, forming sodium chloride

aluminum, when heated in air, forming aluminum oxide

solid ice, when heated, turning into liquid water

sugar, when heated, producing carbon dioxide and water

The pH of lemon juice at 298 cap k is found to be 2 point 3 2 What is the concentration of cap h sub 3 cap o raised to the plus power ions in the solution? Use open bracket cap h sub 3 cap o raised to the plus power close bracket is equal to 10 raised to the negative pH power

9 point 5 5 times 10 squared cap m

2 point 0 9 times 10 squared cap m

4 point 7 9 times 10 to the negative 3 power cap m

1 point 0 5 times 10 to the negative 3 power cap m

A plastic that is composed of a saturated hydrocarbon would have molecules that are most like those in which material?

natural gas

gasoline

lubricating oil

asphalt

A chemist dilutes a 1 point 0 milliliters sample of 2 point 0 cap m KNO sub 3 by adding water to it. If the concentration of the solution that is obtained is 0 point 0 0 8 0 cap m , what is its volume? Use cap m sub i cap v sub i is equal to cap m sub f cap v sub f

125 milliliters

250 milliliters

2 comma 000 milliliters

500 milliliters

Which issue poses the greatest long-term challenge in the development of new nuclear power plants?

storage of radioactive waste

controlling fission reactions

controlling carbon dioxide emissions

mining of uranium

How are large polymers formed?

by combining a few different and larger molecules

by combining many different and smaller molecules

by the addition of halogens to a small molecule

by repetitive combinations of simple subunits

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