Nursing Elites

1. What is the molar mass of Ca(NO3)2?

• A. 74.1 g/mol
• B. 132.1 g/mol
• C. 164.1 g/mol
• D. 78.1 g/mol

Correct answer: B

Rationale: To calculate the molar mass of Ca(NO3)2, we add up the individual atomic masses of its elements: Ca (40.08) + 2N (2 * 14.01) + 6O (6 * 16.00) = 40.08 + 28.02 + 96.00 = 164.1 g/mol. Therefore, the correct answer is 164.1 g/mol (Choice C). Choice A (74.1 g/mol) is incorrect as it does not account for the correct sum of atomic masses. Choice B (132.1 g/mol) is the correct molar mass calculation for Ca(NO3)2. Choice D (78.1 g/mol) is incorrect and does not reflect the accurate molar mass of the compound.

2. What is the primary function of the stomach?

• A. To store food and break it down into smaller pieces
• B. To absorb nutrients into the bloodstream
• C. To produce enzymes that assist in digesting food
• D. To eliminate waste products from the body

Correct answer: A

Rationale: The main function of the stomach is to store food, churn it, and break it down into smaller pieces through mechanical digestion. This process is facilitated by the mixing of food with gastric juices, including stomach acid. The mechanical breakdown in the stomach helps initiate the digestion of food before it progresses to the small intestine for further digestion and nutrient absorption. Absorption of nutrients into the bloodstream primarily occurs in the small intestine, not the stomach. Enzymes that aid in digesting food are primarily produced in the pancreas and small intestine, not in the stomach. The elimination of waste products from the body mainly occurs through the large intestine and rectum, not the stomach.

3. What is the role of the kidneys in the body?

• A. To regulate body temperature
• B. To filter waste from the blood
• C. To produce hormones
• D. To transport oxygen

Correct answer: B

Rationale: The correct answer is B: To filter waste from the blood. The kidneys play a crucial role in filtering waste products and excess substances from the blood to form urine, which helps maintain fluid balance and eliminate toxins from the body. Choice A is incorrect because regulating body temperature is primarily controlled by the skin and other mechanisms. Choice C is incorrect as hormone production is mainly attributed to other organs like the endocrine glands. Choice D is incorrect as the transportation of oxygen is primarily facilitated by the lungs and circulatory system, not the kidneys.

4. What is the difference between a pure substance and a mixture?

• A. Pure substances have a fixed composition, mixtures don't.
• B. Mixtures have a fixed composition, pure substances don't.
• C. Pure substances can be in any state, mixtures are not always solids.
• D. Pure substances are always elements, mixtures are always compounds.

Correct answer: A

Rationale: Pure substances have a definite and constant composition, meaning they are made up of only one type of atom or molecule with fixed proportions. This composition does not vary. On the other hand, mixtures are composed of two or more substances physically combined. The components of a mixture can be present in varying proportions, leading to a variable composition. Choice A is correct as it accurately distinguishes between pure substances and mixtures based on the fixed composition of pure substances and the variable composition of mixtures. Choice B is incorrect because mixtures, not pure substances, have variable compositions. Choice C is incorrect as both pure substances and mixtures can exist in different states. Choice D is incorrect because pure substances can be compounds as well, not exclusively elements, and mixtures can contain elements and compounds.

5. What might happen if blood sugar begins to drop in the human body?

• A. The pancreas releases insulin.
• B. The liver releases stored glucose.
• C. The liver stores glucose as glycogen.
• D. The pancreas releases glucagon.

Correct answer: D

Rationale: When blood sugar levels drop in the body, the pancreas releases glucagon. Glucagon acts to increase blood sugar levels by stimulating the liver to release stored glucose into the bloodstream. Therefore, the correct answer is D. Choice A is incorrect because the release of insulin lowers blood sugar levels, opposite of what happens when blood sugar is dropping. Choice B is incorrect as the liver releases stored glucose in response to low blood sugar, not when blood sugar is already dropping. Choice C is also incorrect as the liver stores glucose as glycogen but doesn't directly impact blood sugar levels dropping in the moment.

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