subtract 12 7 45

HESI A2

Math HESI A2 Practice Test

1. Subtract 12 - 7 4\5.

A. 5 1\5
B. 5 2\5
C. 4 5\6
D. 3 1\3

Correct answer: A

Rationale: Subtract the whole numbers and then subtract the fractions: 12 - 7 4\5 = 5 1\5.

2. According to the Clausius inequality, for a cyclic process involving heat transfer between a system and its surroundings at a single constant temperature (T), the following inequality must hold true:

A. There is no relationship between heat transfer and temperature in a cyclic process.
B. ∫ dQ/T ≥ 0
C. ∫ Q/T = constant
D. ∫ dQ/T ≤ 0

Correct answer: D

Rationale: The Clausius inequality states that for a cyclic process involving heat transfer at a single constant temperature, the integral of heat transfer divided by temperature (∫ dQ/T) must be less than or equal to zero. This inequality reflects the irreversibility of natural processes. Choice A is incorrect as there is a direct relationship between heat transfer and temperature in the Clausius inequality. Choice B is incorrect because the integral of dQ/T must be less than or equal to zero, not greater than or equal to zero. Choice C is incorrect because the integral of Q/T is not a constant in a cyclic process involving heat transfer at a single constant temperature.

3. Which of the following is the weakest intermolecular force?

A. Dipole interactions
B. Hydrogen bonding
C. Van der Waals forces
D. Dispersion forces

Correct answer: D

Rationale: Dispersion forces, also known as London dispersion forces, are the weakest intermolecular forces. They are temporary attractive forces that occur due to momentary shifts in electron distribution within molecules. While dipole interactions, hydrogen bonding, and Van der Waals forces are stronger intermolecular forces, dispersion forces are the weakest because they arise from short-lived fluctuations in electron density. Dipole interactions involve permanent dipoles in molecules, making them stronger than dispersion forces. Hydrogen bonding is stronger than dipole interactions and involves hydrogen atoms bonded to highly electronegative atoms. Van der Waals forces encompass dipole-dipole interactions and dispersion forces, making them stronger than dispersion forces alone.

4. Round to the nearest whole number: 4748 ÷ 12 =

A. 372
B. 384
C. 396
D. 412

Correct answer: C

Rationale: To find the answer, divide 4748 by 12: 4748 ÷ 12 = 395.666... Since we are rounding to the nearest whole number, we round up to 396 because the decimal part (.666) is greater than .5. Choice A (372) is too low as it does not account for the decimal value. Choice B (384) is also too low. Choice D (412) is too high as it goes beyond the correct rounded value.

5. A doctor orders 1 gram of a medication to be administered intravenously. The available vial contains 200 milligrams per milliliter. How many milliliters of the solution should be drawn up?

A. 4 milliliters
B. 5 milliliters
C. 10 milliliters
D. 20 milliliters

Correct answer: B

Rationale: 1 gram is equivalent to 1000 milligrams. The concentration of the medication is 200 milligrams per milliliter. To calculate the volume needed, divide the total amount of medication by the concentration: 1000 mg / 200 mg/mL = 5 mL. Therefore, 5 milliliters of the solution should be drawn up to administer 1 gram of the medication intravenously. Choice A (4 milliliters), Choice C (10 milliliters), and Choice D (20 milliliters) are incorrect because they do not accurately calculate the volume of the solution needed based on the concentration of the medication.