Question 1

The volume in liters of a 0.2M solution of NaOH needed to neutralize 2 liters of a 0.03M solution of HCl is

Options :

A : 0.3 L

B : 0.03 L

C : 0.1 L

D : 0.01 L

E : 0.2 L

Answer: A

Question 2

Which of the following are allotropes?

Options :

A : NH3, NH4 +

B : H,O, H,S

C : C(graphite)' C(diamond)

D : He, Ne

E : N2, O2

Answer: C

Question 3

In an aquatic environment, oxygen concentration depends on chemical and physical factors and is greatly

affected by many biological processes. These is much less dissolved oxygen (DO) in aquatic environments

than in dry air. In most aquatic environments, there are only 5 to 10 mL of dissolved oxygen in a liter of

water. Chemical and physical factors, such as salinity, pH, and especially temperature, can affect the DO

concentration and distribution. An experiment was done to study the effect of different salinity levels on DO

in water of varying temperatures. The results are below. Salinity is expressed in parts per thousand (ppt)

and is the content of dissolved salt in water.

CLEP-Science-and-Mathematics-page205-image13

The results of the experiment suggest that at salinities of greater than 30 ppt, it is likely that

Options :

A : dissolved oxygen levels would increase

B : water temperature would increase

C :

aquatic organisms would begin to die

D : there would be no change in dissolved oxygen

E :

the amount of dissolved oxygen would decrease

Answer: A

Question 4

Organisms in which type of relationship both benefit from their association?

Options :

A : Mutualism

B :

Parasitism

C : Commensalism

D : Antagonism

E : None of the above

Answer: A

Question 5

Guard cells are kidney-shaped cells surrounding the stomata on the underside of leaves. These cells

change their shape according to the amount of water that exists within them. The more water within, the

more swollen the guard cells are and the stomata open. When water is sparse the guard cells shrivel and

close the stomata. Recent evidence suggests that there are blue-light receptors on the plasma membrane

surface of guard cells that are coupled to potassium (K+) ion channels. K+ ions are normally found in high

concentration outside guard cell membranes when the channels are closed.

What mechanism may account for the fact that guard cells are usually open during the day and closed at

night?

Options :

A :

Photosynthesis uses K+ ions; therefore, lower concentrations of potassium within the leaf drive the

movement of K+ into the leaf through the guard cells.

B :

The presence of sunlight drives K+ into guard cells, while driving water out of the guard cells and

opening the stomata.

C : There is more water in the air during daylight hours than during nighttime hours.

D : K+ ions enter the cell through active transport only when enough water is present.

E :

The presence of sunlight opens the K+ ion channels, driving potassium inside, and causing water to

follow by osmosis, swelling the guard cells.

Answer: A

Free CLEP-Science-and-Mathematics Mock Exam – Practice Online Confidently

Buying Options: