Q: Which of the following is a correct statement about the mole concept?

One mole of any substance contains $$6.022 \times 10$$^{23}$$ particles.

Question 1

Which of the following best describes the difference between an ionic bond and a covalent bond?

Accepted Answer

An ionic bond involves the transfer of electrons from a metal to a nonmetal, while a covalent bond involves the sharing of electrons between two nonmetals.

Question 2

A student measures the mass of a sample as 12.30 g and its volume as 4.1 mL. What is the density of the sample, reported with the correct number of significant figures?

Accepted Answer

$$3.0\ \mathrm{g/mL}$$

Question 3

Which of the following is the correct electron configuration for a neutral atom of phosphorus ($$Z=15$$)?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^6$$\ $$3s^2$$\ $$3p^3$$

Question 4

A radioactive isotope has a half-life of 8 hours. If you start with a 160 mg sample, how much remains after 24 hours?

Accepted Answer

$$20\ \mathrm{mg}$$

Question 5

Which of the following statements about acids and bases is correct?

Accepted Answer

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

Question 6

Which of the following best explains why water is a polar molecule?

Accepted Answer

Water has a bent molecular geometry and an unequal distribution of electrons.

Question 7

A sample of gas occupies $$2.50\ \mathrm{L} at$$ $$1.00\ \mathrm{atm}$$ and $$300\ \mathrm{K}. $$What will be its volume at $$2.00\ \mathrm{atm}$$ and $$300\ \mathrm{K}$$, assuming the amount of gas remains constant?

Accepted Answer

$$1.25\ \mathrm{L}$$

Question 8

Which of the following laboratory safety practices is most important when working with concentrated acids?

Accepted Answer

Wearing chemical splash goggles and a lab coat at all times.

Question 9

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

Accepted Answer

$$\mathrm{HCl} + \mathrm{NaOH} \rightarrow \mathrm{NaCl} + \mathrm{H}_2\mathrm{O}$$

Question 10

A solution is prepared by dissolving $$10.0\ \mathrm{g} of $$NaCl in enough water to make $$250.0\ \mathrm{mL} of $$solution. What is the molarity of the solution? ($$\mathrm{NaCl}$$ molar mass $$= 58.44\ \mathrm{g/mol})$$

Accepted Answer

$$0.684\ \mathrm{M}$$

Question 11

Which of the following best describes the process of osmosis?

Accepted Answer

The movement of solvent molecules from low solute concentration to high solute concentration through a semipermeable membrane.

Question 12

Which of the following is the correct IUPAC name for the compound with the formula $$\mathrm{CH}_3\mathrm{CH}_2\mathrm{OH}$$?

Accepted Answer

Ethanol

Question 13

A chemical reaction has an activation energy of $$50\ \mathrm{kJ/mol}$$ and releases $$100\ \mathrm{kJ/mol} of $$energy. Which of the following statements is true?

Accepted Answer

The reaction is exothermic and releases energy to the surroundings.

Question 14

Which of the following best describes a buffer solution?

Accepted Answer

A solution that contains a weak acid and its conjugate base.

Question 15

Which of the following is a correct statement about the mole concept?

Accepted Answer

One mole of any substance contains $$6.022 	imes 10$$^{23}$$ particles.

Question 16

A student is asked to prepare $$100.0\ \mathrm{mL} of a$$ $$0.200\ \mathrm{M}$$ NaOH solution from a $$1.00\ \mathrm{M}$$ stock solution. What volume of the stock solution should be used?

Accepted Answer

$$20.0\ \mathrm{mL}$$

Question 17

Which of the following is a correct nuclear equation for the beta decay of carbon-14?

Accepted Answer

$$^{14}_{6}\mathrm{C} \$$rightarrow ^{14}$$_{7}\mathrm{N} $$+ ^{0}$$_{-1}\beta$$

Question 18

Which of the following best describes the difference between precision and accuracy in laboratory measurements?

Accepted Answer

Precision refers to how close measurements are to each other, while accuracy refers to how close measurements are to the true value.

Question 19

Which of the following is the correct Lewis structure for carbon dioxide ($$\mathrm{CO}_2$$)?

Accepted Answer

O=C=O, with each oxygen atom having two lone pairs.

Chemistry 10: General, Organic, and Biological Chemistry – Course Overview and Study Guide

Guida di studio - Domande di pratica

Study guide - Flashcard