which of the following is an example of a weak acid

ATI TEAS 7

Mometrix TEAS 7 science practice test

1. Which of the following is an example of a weak acid?

A. Hydrochloric acid (HCl)
B. Sulfuric acid (H2SO4)
C. Acetic acid (CH3COOH)
D. Nitric acid (HNO3)

Correct answer: C

Rationale: The correct answer is Acetic acid (CH3COOH) because it is a weak acid that only partially dissociates in water, resulting in a lower concentration of H+ ions compared to strong acids like hydrochloric acid (HCl), sulfuric acid (H2SO4), and nitric acid (HNO3) which completely dissociate in water. Weak acids do not fully ionize in water, leading to a lower concentration of H+ ions in solution. Hydrochloric acid, sulfuric acid, and nitric acid are strong acids that completely dissociate in water, producing a higher concentration of H+ ions. Therefore, they are not examples of weak acids.

2. Which of the following is LEAST likely to be found in a human cell's genes?

A. Sequences of amino acids to be transcribed into mRNA
B. Lethal recessive traits like sickle cell anemia
C. Mutated DNA
D. DNA that codes for proteins the cell doesn't use

Correct answer: D

Rationale: Human cells typically contain genes that code for proteins necessary for the cell's functions. DNA that codes for proteins the cell doesn't use would be an inefficient use of the cell's resources. Therefore, it is less likely to be found in a human cell's genes. Options A, B, and C are more commonly associated with genes found in human cells. Choice A refers to the genetic information needed for protein synthesis, while choice B involves traits that can be present in the gene pool. Mutated DNA (choice C) can also be found in human cells as a result of genetic alterations. However, DNA that codes for proteins not utilized by the cell would be redundant and not typically retained in the genome.

3. A student hypothesizes that higher sugar consumption negatively impacts test scores. To investigate this, the student recruits participants to consume varying amounts of sugar, wait for one hour, and then complete an aptitude test. The student will record both the amount of sugar consumed and the test scores to analyze the relationship. What is the best experimental approach?

A. Conduct one round of testing where each participant consumes a different amount of sugar.
B. Conduct two rounds of testing: In the first round, participants consume varying amounts of sugar; in the second round, they consume the same amount of sugar as they did in the first round.
C. Conduct two rounds of testing: In the first round, participants consume varying amounts of sugar; in the second round, participants consume no sugar.
D. Conduct one round of testing where all participants consume the same amount of sugar.

Correct answer: C

Rationale: Option C provides the most thorough experimental design by including a control group. In the first round, varying sugar intake levels help explore the relationship between sugar consumption and test scores. In the second round, by having participants consume no sugar, the student can compare results to observe any changes due to sugar intake. This approach enhances the validity of the findings by accounting for potential confounding factors and better identifying causal relationships. Choice A is not ideal as it lacks a control group and does not compare the impact of sugar consumption. Choice B does not explore the effects of sugar consumption adequately as it does not include a group without sugar. Choice D does not allow for comparison between different sugar consumption levels, limiting the ability to draw meaningful conclusions.

4. What is the name of the growth plates in children's bones where new bone tissue is formed?

A. Epiphyses
B. Diaphysis
C. Periosteum
D. Medullary cavity

Correct answer: A

Rationale: The correct answer is A: Epiphyses. Epiphyses are cartilaginous areas found at the ends of long bones, enabling growth and bone lengthening during childhood and adolescence. The diaphysis refers to the main shaft of a long bone. The periosteum is the outer bone layer responsible for nourishment and aiding in bone repair. The medullary cavity is the central cavity within the diaphysis that contains bone marrow but is not involved in new bone tissue formation.

5. What is the relationship between the frequency and period of a wave?

A. They are unrelated
B. Frequency = Period
C. Frequency = 1/Period
D. Period = 1/Frequency

Correct answer: D

Rationale: The correct relationship between frequency and period of a wave is that Period = 1/Frequency. This relationship indicates that the period of a wave is the reciprocal of its frequency. Frequency refers to the number of complete cycles of a wave occurring in a unit of time, while the period is the time taken for one complete cycle of the wave to occur. As frequency and period are inversely related, the correct formula to express this relationship is Period = 1/Frequency. Choice A is incorrect as frequency and period are related. Choice B is incorrect as frequency and period are not equal. Choice C is incorrect as it suggests that frequency is directly proportional to period, which is not the case.