Question of the Day

12/29/20

Two charges separated by 1 m exert a 1 N force on each other. What is the force on each charge when they are separated by a distance of 3 m?

A. 3 N

B. 0.33 N

C. 0.11 N

D. 0.73 N


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Correct answer: C

According to Coulomb’s law, the electrical force between two charged objects is directly proportional to the product of the quantity of charge on the objects and inversely proportional to the square of the separation distance between the two objects.

F=KQ1Q2/r2

12/28/20

John receives a speeding ticket, which then decreases his behavior of speeding. This is an example of:

A. Positive reinforcement

B. Positive punishment

C. Negative reinforcement

D. Negative punishment


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Correct answer: B

  • Positive punishment is the addition of an unpleasant stimulus (positive) to decrease a behavior (punishment).

  • Negative punishment is the removal of a pleasant stimulus (negative) to decrease a behavior (punishment).

  • Positive reinforcement is the addition of a pleasant stimulus (positive) to increase/maintain a behavior (reinforcement).

  • Negative reinforcement is the removal of an unpleasant stimulus (negative) to increase/maintain a behavior (reinforcement).

12/27/20

Which of the following is necessary for a spontaneous reaction?

A. The entropy of the universe increases

B. The temperature of the universe increases

C. The enthalpy of the universe increases

D. The free energy of the universe increases


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Correct answer: A

The second law of thermodynamics states that in any spontaneous process there is always an increase in the entropy of the universe.

12/23/20

A monoprotic weak acid is titrated with a strong base. At the first equivalence point, the pH will be:

A. 7

B. less than 7

C. more than 7

D. Not enough information is provided


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Correct answer: C

At the equivalence point, the acid has been converted entirely into its conjugate base, which will be weakly basic. Thus, the pH will be more than 7.

12/22/20

The SI unit of electrical current is:

A. Farads

B. Ohms

C. Volts

D. Amperes


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Correct answer: D

12/17/20

Which of the following contains a functional group consisting of an acyl group (R-C=O) linked to a nitrogen atom?

A. Amide

B. Ester

C. Ketone

D. Thiol


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Correct answer: A

12/16/20

A gas at a temperature of 27°C has a volume of 80 mL. What temperature change will increase this gas to a volume of 120 mL?

A. Increase of 13.5°C

B. Decrease of 13.5°C

C. Increase of 150°C

D. Decrease of 150°C


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Correct answer: B

12/15/20

Fatty acids enter the catabolic pathway in the form of:

A. Acetyl-CoA

B. Adipose tissue

C. Glycerol

D. Ketone bodies


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Correct answer: A

12/14/20

What is the oxidation number of potassium in KMnO4?

A. -2

B. -1

C. 0

D. +1


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Correct answer: D

12/11/20

Most amino acids exist as _?_ in a neutral solution.

A. positively charged compounds

B. negatively charged compounds

C. zwitterions

D. none of the above


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Correct answer: C

12/10/20

Recalling that Washington D.C. is the capital of the United States is an example of:

A. Episodic Memory

B. Procedural Memory

C. Semantic Memory

D. Working Memory


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Correct answer: C

12/8/20

Where does B-oxidation of fatty acids occur inside the cell?

A. Plasma membrane

B. Mitochondria

C. Nucleus

D. Cytosol


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Correct answer: B

12/7/20

The _?_ is a thin layer of nerve tissue lining the inner back wall of the eye.

A. Retina

B. Iris

C. Cornea

D. Lens


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Correct answer: A

12/6/20

Which amino acid will produce the most energy when degraded?

A. Alanine

B. Glycine

C. Isoleucine

D. Valine


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Correct answer: C

12/5/20

Which of the following is NOT a function of the cell membrane?

A. Transport regulation

B. Cytoskeletal attachment

C. Protein synthesis

D. Second messenger reservoir


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Correct answer: C

12/2/20

At pH 7, the charge on a molecule of glutamic acid is:

A. -2

B. -1

C. 0

D. +1


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Correct answer: B

12/1/20

How do enzymes increase the rate of a reaction?

A. increasing activation energy

B. decreasing activation energy

C. increasing the overall free energy change of the reaction

D. decreasing the overall free energy change of the reaction


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Correct answer: B