Q: Which of the following is the correct formula for calculating the percent yield of a chemical reaction?

$$\text{Percent Yield} = \frac{\text{Actual Yield}}{\text{Theoretical Yield}} \times 100$$

Question 1

Which of the following best describes the difference between organic and inorganic compounds?

Accepted Answer

Organic compounds are primarily composed of carbon and hydrogen, while inorganic compounds generally do not contain both.

Question 2

A patient is given a medication that is a weak acid. Which of the following will increase the amount of the non-ionized (absorbable) form of the drug in the stomach?

Accepted Answer

Decreasing the pH of the stomach.

Question 3

Which of the following is the correct scientific notation for the number 0.00056?

Accepted Answer

$$5.6 	imes 10$$^{-4}$$

Question 4

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 5

A solution is prepared by dissolving 5.0 g of NaCl in enough water to make 250 mL of solution. What is the molarity of the solution? ($$M_{NaCl} = 58.44 \ g/mol)$$

Accepted Answer

$$0.34 \ mol/L$$

Question 6

Which of the following best explains why water is a good solvent for ionic compounds?

Accepted Answer

Water molecules have a dipole moment that allows them to surround and separate ions.

Question 7

Which of the following is the correct balanced equation for the reaction of hydrochloric acid with sodium hydroxide?

Accepted Answer

$$HCl + NaOH \rightarrow NaCl + H_2O$$

Question 8

A sample of gas occupies 2.0 L at 1.0 atm. If the pressure is increased to 4.0 atm at constant temperature, what will be the new volume?

Accepted Answer

$$0.5 \ L$$

Question 9

Which of the following is a correct statement about acids and bases according to the Brønsted-Lowry definition?

Accepted Answer

An acid is a substance that donates a proton.

Question 10

Which of the following functional groups is present in all amino acids?

Accepted Answer

Both carboxyl ($$-COOH) $$and amino ($$-NH_2$) groups

Question 11

A carbohydrate is classified as a monosaccharide if it:

Accepted Answer

Contains only one sugar unit.

Question 12

Which of the following is the correct formula for calculating the percent yield of a chemical reaction?

Accepted Answer

$$	ext{Percent Yield} = \frac{	ext{Actual Yield}}{	ext{Theoretical Yield}} 	imes 100$$

Question 13

Which of the following best describes the role of enzymes in metabolic pathways?

Accepted Answer

Enzymes act as biological catalysts to speed up chemical reactions.

Question 14

Which of the following is the correct formula for calculating the energy of a photon?

Accepted Answer

$$E = h 
u$$

Question 15

A buffer solution is made by mixing acetic acid and sodium acetate. What is the main function of this buffer in a biological system?

Accepted Answer

To maintain a constant pH when small amounts of acid or base are added.

Question 16

Which of the following is the correct formula for calculating the number of moles from mass and molar mass?

Accepted Answer

$$	ext{Moles} = \frac{	ext{Mass}}{	ext{Molar Mass}}$$

Question 17

Which of the following statements about lipids is correct?

Accepted Answer

Lipids are nonpolar molecules and are insoluble in water.

Question 18

Which of the following is the correct formula for the ideal gas law?

Accepted Answer

$$PV = nRT$$

Question 19

Which of the following is a correct statement about the periodic table?

Accepted Answer

Elements in the same group have similar chemical properties.

Question 20

Which of the following is the correct formula for calculating the density of a substance?

Accepted Answer

$$	ext{Density} = \frac{	ext{Mass}}{	ext{Volume}}$$

Introductory Chemistry for GOB Students: Structured Study Guide

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