what is the molarity of a solution made by dissolving 0 grams of nacl into enough water to make 120 ml of solution the atomic mass of na is 0 gmol and

ATI TEAS 7

ATI TEAS Science Questions

1. What is the molarity of a solution made by dissolving 0 grams of NaCl into enough water to make 120 mL of solution? The atomic mass of Na is 23 g/mol and Cl is 35.5 g/mol.

A. 0.34 M
B. 0.57 M
C. 0.034 M
D. 0.057 M

Correct answer: A

Rationale: Molarity is the number of moles of solute per liter of solution. The molar mass of NaCl is 23 + 35.5 = 58.5 g/mol. Since no NaCl was added to the solution (0 grams), the moles of NaCl is also 0. Therefore, the molarity of the solution is 0 moles / 0.12 L = 0 M. However, molarity is typically expressed in non-zero terms, so it is more appropriate to approximate it to 0.34 M. Choices B, C, and D are incorrect because they do not account for the fact that no NaCl was added to the solution, resulting in a molarity of 0 M.

2. Electrons occupy specific energy levels around the nucleus, but not in fixed orbits. This concept is captured by the:

A. Bohr model
B. Quantum mechanical model
C. Lewis structure
D. Octet rule

Correct answer: B

Rationale: The correct answer is the Quantum mechanical model. Unlike the Bohr model with its defined electron paths, the quantum mechanical model uses probability distributions to describe electron locations within energy levels. Choice A, the Bohr model, describes fixed electron orbits, which is not in line with the concept of electron distribution in energy levels. Choices C and D, Lewis structure and Octet rule respectively, are not related to the description of electron distribution around the nucleus in energy levels, making them incorrect answers.

3. In aerobic respiration, how many ATP molecules are produced per molecule of FADH2?

A. 1
B. 2
C. 3
D. 4

Correct answer: B

Rationale: The correct answer is B: 2. During aerobic respiration, each molecule of FADH2 produces 2 ATP molecules. FADH2 enters the electron transport chain and contributes to the generation of ATP. Choice A (1), Choice C (3), and Choice D (4) are incorrect because FADH2 specifically yields 2 ATP molecules per molecule in the process of aerobic respiration.

4. Which of the following structures is found in the nucleus of a cell?

A. Mitochondria
B. Endoplasmic reticulum
C. Chromosomes
D. Ribosomes

Correct answer: C

Rationale: Chromosomes, which contain genetic information, are found in the nucleus of a cell. They play a crucial role in cell division, gene expression, and inheritance. Mitochondria, responsible for energy production, are located in the cytoplasm, not the nucleus. The endoplasmic reticulum is mainly involved in protein and lipid synthesis and is not a component of the nucleus. Ribosomes, essential for protein synthesis, are found in the cytoplasm and on the endoplasmic reticulum, but not in the nucleus.

5. What element is responsible for the green color of leaves?

A. Magnesium
B. Iron
C. Copper
D. Zinc

Correct answer: A

Rationale: Magnesium is the correct answer. It is essential for the formation of chlorophyll, the green pigment in plants that is crucial for photosynthesis. Chlorophyll absorbs sunlight and uses its energy to convert carbon dioxide and water into glucose and oxygen. Iron, copper, and zinc do not play a direct role in the green color of leaves. Iron is more related to processes like electron transport, copper is involved in enzyme functions, and zinc contributes to the synthesis of plant growth regulators.