Q: Calculate the molecular weight of water ($$\mathrm{H}_2\mathrm{O}) $$using the atomic masses: H = 1.0 amu, O = 16.0 amu.

$$2 \times 1.0 + 16.0 = 18.0$$ amu

Q: A sample contains $$4.0 g of $$carbon. How many atoms of carbon are present? (Atomic mass of C = $$12.0 g/$$mol, Avogadro's number $$= 6.022 \times 10$$^{23}$$ atoms/mol)

$$\frac{4.0}{12.0} \times 6.022 \times 10$$^{23}$$ = 2.0 \times 10$$^{23}$$ atoms

Q: Which of the following is the correct mole-to-atom conversion factor for oxygen atoms?

$$1$$ mol O $$= 6.022 \times 10$$^{23}$$ atoms O

Q: How many moles of hydrogen are present in $$10.0 g of $$acetic acid ($$\mathrm{C}_2\mathrm{H}_4\mathrm{O}_2$$)? (Molar mass of acetic acid $$= 60.0 g/$$mol)

$$\frac{10.0}{60.0} \times 4 = 0.67$$ mol H

Q: Which of the following is the correct molar mass for glucose ($$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6) $$given C = 12.0 g/mol, H = 1.0 g/mol, O = 16.0 g/mol?

$$6 \times 12.0 + 12 \times 1.0 + 6 \times 16.0 = 180.0 g/$$mol

Question 1

Which subatomic particle determines the identity of an element?

Accepted Answer

Proton

Question 2

A neutral atom of sodium (Na) has an atomic number of 11 and a mass number of 23. How many neutrons does it have?

Accepted Answer

$$23 - 11 = 12$$ neutrons

Question 3

Which of the following best describes an isotope?

Accepted Answer

Atoms with the same number of protons but different numbers of neutrons

Question 4

What is the correct symbol for an atom with 29 protons, 36 neutrons, and 29 electrons?

Accepted Answer

$$^{65}\mathrm{Cu}$$

Question 5

Which of the following statements about ions is correct?

Accepted Answer

An ion is formed when an atom gains or loses electrons

Question 6

Calculate the molecular weight of water ($$\mathrm{H}_2\mathrm{O}) $$using the atomic masses: H = 1.0 amu, O = 16.0 amu.

Accepted Answer

$$2 	imes 1.0 + 16.0 = 18.0$$ amu

Question 7

How many atoms of oxygen are present in one molecule of acetic acid ($$\mathrm{C}_2\mathrm{H}_4\mathrm{O}_2$$)?

Accepted Answer

2

Question 8

A sample contains $$4.0 g of $$carbon. How many atoms of carbon are present? (Atomic mass of C = $$12.0 g/$$mol, Avogadro's number $$= 6.022 	imes 10$$^{23}$$ atoms/mol)

Accepted Answer

$$\frac{4.0}{12.0} 	imes 6.022 	imes 10$$^{23}$$ = 2.0 	imes 10$$^{23}$$ atoms

Question 9

Which of the following is the correct mole-to-atom conversion factor for oxygen atoms?

Accepted Answer

$$1$$ mol O $$= 6.022 	imes 10$$^{23}$$ atoms O

Question 10

A neutral atom of sulfur ($$\mathrm{S}) $$has an atomic number of 16. If it gains two electrons, what is its resulting charge?

Accepted Answer

$$2-$$

Question 11

Which statement best explains why atomic mass is not always a whole number?

Accepted Answer

Atomic mass is a weighted average of all naturally occurring isotopes

Question 12

How many moles of hydrogen are present in $$10.0 g of $$acetic acid ($$\mathrm{C}_2\mathrm{H}_4\mathrm{O}_2$$)? (Molar mass of acetic acid $$= 60.0 g/$$mol)

Accepted Answer

$$\frac{10.0}{60.0} 	imes 4 = 0.67$$ mol H

Question 13

Which of the following is a correct classification for the element calcium ($$\mathrm{Ca}$$)?

Accepted Answer

Alkaline Earth Metal

Question 14

A molecule of glucose ($$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6) $$contains how many total atoms?

Accepted Answer

$$6 + 12 + 6 = 24$$ atoms

Question 15

Which of the following is the correct formula weight for sodium chloride ($$\mathrm{NaCl}) $$given Na = 23.0 amu and Cl = 35.5 amu?

Accepted Answer

$$23.0 + 35.5 = 58.5$$ amu

Question 16

If an atom has 15 protons, 16 neutrons, and 18 electrons, what is its charge and classification?

Accepted Answer

Charge: $$3-$$, Classification: Ion

Question 17

Which of the following is the correct molar mass for glucose ($$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6) $$given C = 12.0 g/mol, H = 1.0 g/mol, O = 16.0 g/mol?

Accepted Answer

$$6 	imes 12.0 + 12 	imes 1.0 + 6 	imes 16.0 = 180.0 g/$$mol

Question 18

Which of the following best describes the relationship between atomic number and mass number?

Accepted Answer

Mass number = atomic number + number of neutrons

Question 19

A compound contains 2 moles of hydrogen and 1 mole of oxygen. What is the empirical formula?

Accepted Answer

$$\mathrm{H}_2\mathrm{O}$$

Chap 2Atoms and Molecules: Structure, Properties, and Calculations

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드