how many moles of potassium bromide are in 25 ml of a 4 m kbr solution

HESI A2

HESI A2 Chemistry Practice Questions

1. How many moles of potassium bromide are in 25 mL of a 4 M KBr solution?

A. 0.035 mol
B. 0.1 mol
C. 0.18 mol
D. 1.6 mol

Correct answer: B

Rationale: To find the moles of potassium bromide in 25 mL of a 4 M KBr solution, we first need to convert the volume from milliliters to liters. 25 mL is equal to 0.025 L. Then, we use the formula moles = molarity x volume in liters. Substituting the values, moles = 4 M x 0.025 L = 0.1 mol. Therefore, there are 0.1 moles of KBr in 25 mL of a 4 M solution. Choice A, 0.035 mol, is incorrect as it does not properly calculate the moles. Choice C, 0.18 mol, and choice D, 1.6 mol, are also incorrect as they are not the result of the correct calculation based on the given molarity and volume.

2. Which word is not spelled correctly? The government official was grateful to receive that award.

A. government
B. official
C. grateful
D. receive

Correct answer: A

Rationale: The correct spelling of the word is 'government' with an 'n' after the 't.' In the sentence provided, the word 'goverment' is misspelled, making it the correct answer choice. Choices B, C, and D are all spelled correctly within the context of the sentence, so they are not the correct answer.

3. Select the meaning of the word 'holistic' in the sentence: 'Dr. Grant ignored Mary's particular symptoms, instead administering a holistic treatment.'

A. insensitive
B. ignorant
C. specialized
D. concerned with the whole

Correct answer: D

Rationale: In this context, 'holistic' means concerned with the whole person, considering physical, mental, and social factors, rather than just addressing specific symptoms. Therefore, the correct answer is D. Choices A, B, and C are incorrect because 'holistic' does not mean insensitive, ignorant, or specialized in this context.

4. Multiply: 32 × 5 and express the result in decimal form.

A. 0.0016
B. 0.016
C. 0.16
D. 1.6

Correct answer: D

Rationale: To find the product of 32 and 5, you simply multiply the two numbers: 32 × 5 = 160. Therefore, when expressed in decimal form, the answer is 1.6. Choices A, B, and C are incorrect as they do not represent the correct multiplication result in decimal form. Choice A is way too small, choice B is also too small, and choice C is close but still not the correct result.