Q: A student needs to convert 5.0 grams of NaCl to moles. Which equation should they use, and what is the correct answer if the molar mass of NaCl is 58.44 g/mol?

Use $$\text{moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}}$$; $$\frac{5.0}{58.44} = 0.086$$ moles.

Q: A solution is prepared by dissolving 10.0 g of glucose ($$C_6H_{12}O_6$) in enough water to make 250 mL of solution. What is the molarity of the solution? (Molar mass of glucose = 180.16 g/mol)

$$\text{Molarity} = \frac{\text{moles of solute}}{\text{liters of solution}} = \frac{10.0/180.16}{0.250} = 0.222\ \text{M}$$

Q: A nurse needs to prepare 500 mL of a 0.9% (w/v) NaCl solution for intravenous use. How many grams of NaCl are required?

$$0.9\% = 0.9\ \text{g NaCl} / 100\ \text{mL solution}$$, so $$0.9 \times 5 = 4.5 g $$NaCl.

Q: Which equation would you use to calculate the energy required to heat 100 g of water from 25°C to 75°C? (Specific heat of water = $$4.18\ \text{J/g}^\circ\text{C})$$

$$q = m \times c \times \Delta T = 100 \times 4.18 \times (75-25) = 20,900\ \text{J}$$

Q: Which of the following is a correct application of dimensional analysis for converting 2.5 L to mL?

$$2.5\ \text{L} \times \frac{1000\ \text{mL}}{1\ \text{L}} = 2500\ \text{mL}$$

Question 1

Which of the following best describes the main focus of Chemistry B11 as outlined in the syllabus?

Accepted Answer

A qualitative and quantitative introduction to general, organic, and biochemistry, including physical principles, inorganic and organic compounds, and biochemical reactions.

Question 2

A student needs to convert 5.0 grams of NaCl to moles. Which equation should they use, and what is the correct answer if the molar mass of NaCl is 58.44 g/mol?

Accepted Answer

Use $$	ext{moles} = \frac{	ext{mass (g)}}{	ext{molar mass (g/mol)}}$$; $$\frac{5.0}{58.44} = 0.086$$ moles.

Question 3

Which of the following is a correct safety practice required in the Chemistry B11 laboratory?

Accepted Answer

Wearing chemical-resistant safety goggles that meet ANSI Z-87.1 standards at all times during experiments.

Question 4

A solution is prepared by dissolving 10.0 g of glucose ($$C_6H_{12}O_6$) in enough water to make 250 mL of solution. What is the molarity of the solution? (Molar mass of glucose = 180.16 g/mol)

Accepted Answer

$$	ext{Molarity} = \frac{	ext{moles of solute}}{	ext{liters of solution}} = \frac{10.0/180.16}{0.250} = 0.222\ 	ext{M}$$

Question 5

Which of the following statements about the periodic table is correct according to the course objectives?

Accepted Answer

Elements in the same group have similar chemical properties due to similar valence electron configurations.

Question 6

A nurse needs to prepare 500 mL of a 0.9% (w/v) NaCl solution for intravenous use. How many grams of NaCl are required?

Accepted Answer

$$0.9\% = 0.9\ 	ext{g NaCl} / 100\ 	ext{mL solution}$$, so $$0.9 	imes 5 = 4.5 g $$NaCl.

Question 7

Which of the following best describes the function of a buffer in a biological system?

Accepted Answer

A buffer resists changes in pH when small amounts of acid or base are added.

Question 8

Which equation would you use to calculate the energy required to heat 100 g of water from 25°C to 75°C? (Specific heat of water = $$4.18\ 	ext{J/g}^\circ	ext{C})$$

Accepted Answer

$$q = m 	imes c 	imes \Delta T = 100 	imes 4.18 	imes (75-25) = 20,900\ 	ext{J}$$

Question 9

Which of the following is a correct application of dimensional analysis for converting 2.5 L to mL?

Accepted Answer

$$2.5\ 	ext{L} 	imes \frac{1000\ 	ext{mL}}{1\ 	ext{L}} = 2500\ 	ext{mL}$$

Question 10

Which of the following is a correct statement about acids and bases according to the course objectives?

Accepted Answer

Acids donate protons ($$H^+) $$and bases accept protons in aqueous solutions.

Question 11

A student is asked to identify the functional group in ethanol ($$CH_3CH_2OH). $$Which group is present?

Accepted Answer

Hydroxyl group ($$-OH)$$

Question 12

Which of the following is a correct example of applying laboratory safety rules?

Accepted Answer

Tying back long hair and wearing a lab coat during experiments.

Question 13

Which of the following best describes the role of enzymes in metabolism?

Accepted Answer

Enzymes act as biological catalysts, speeding up metabolic reactions without being consumed.

Question 14

A solution has a pH of 4. What is the $$[H^+]$$ concentration?

Accepted Answer

$$[H^+] = 10$$^{-4}$$\ 	ext{M}$$

Question 15

Which of the following is a correct statement about osmosis?

Accepted Answer

Osmosis is the movement of water across a semipermeable membrane from low solute concentration to high solute concentration.

Question 16

Which of the following is the correct formula for calculating percent composition by mass?

Accepted Answer

$$\%\ 	ext{composition} = \frac{	ext{mass of component}}{	ext{total mass}} 	imes 100$$

CHEM B11: Introduction to General, Organic, and Biochemistry – Syllabus and Course Schedule Study Guide

Guida di studio - Domande di pratica

Study guide - Flashcard