Which of the following best describes the result of using a catalyst in a chemical reaction?
A. A more desirable product is often formed.
B. The reaction is completed in a shorter amount of time.
C. A greater amount of heat energy is released by the reaction.
D. The yield of product is increased.
The result of using a catalyst in a chemical reaction is that the reaction is completed in a shorter amount of time ¹. A catalyst is a chemical substance that affects the rate of a chemical reaction by altering the activation energy required for the reaction to proceed ¹. This process is called catalysis ¹. A catalyst provides an alternative pathway for the reaction, one that has a lower activation energy than the uncatalyzed pathway .
The other options are not correct because they do not accurately describe the result of using a catalyst in a chemical reaction. A more desirable product is not necessarily formed, a greater amount of heat energy is not necessarily released by the reaction, and the yield of product is not necessarily increased as a result of using a catalyst.
Therefore, the Correct Answer is B.
More Questions on TEAS 7 Science
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Q #1: A study found two processes, Process A and Process B, to be correlated. Which of the following is true for these processes?
A. The study indicates that Process A causes Process B.
B. The study cannot indicate whether Process A and B have a positive relationship.
C. The study does not indicate a causal relationship between the processes.
D. The study cannot indicate whether Process A and B have a negative relationship.
Answer Explanation
The correct answer is c.
The study does not indicate a causal relationship between the processes. A correlation between two processes means that there is a statistical relationship between them, but it does not necessarily imply causation. In other words, just because two processes are correlated does not mean that one causes the other.
b.The study does not indicate that Process A causes Process B.
b.The study can indicate whether Process A and B have a positive relationship if the correlation is positive.
d. The study can indicate whether Process A and B have a negative relationship if the correlation is negative.
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Q #2: Which of the following structures is an exocrine gland?
A. Pineal gland
B. Parathyroid gland
C. Parotid gland
D. Pituitary gland
Answer Explanation
The parotid gland is an exocrine gland that secretes saliva into the mouth. Exocrine glands secrete their products into ducts that carry the secretions to the body's surface or into body cavities. The other options are endocrine glands, which secrete hormones directly into the bloodstream. The pineal gland secretes melatonin, the parathyroid glands secrete parathyroid hormone, and the pituitary gland secretes several hormones that regulate various bodily functions.
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Q #3: Which of the following ions binds to the troponin complex, initiating the contraction of a muscle?
A. Sodium
B. Potassium
C. Calcium
D. Phosphorus
Answer Explanation
When a muscle cell is stimulated by a nerve impulse, calcium ions are released from the sarcoplasmic reticulum into the cytoplasm. The calcium ions bind to the troponin complex, which is a protein that regulates the interaction between actin and myosin filaments. The binding of calcium to troponin causes a conformational change that exposes the binding sites for myosin on the actin filaments. This allows the myosin heads to attach to the actin and pull the filaments past each other, resulting in muscle contraction.
