Q: A sample of calcium carbonate contains 8.0 g calcium, 2.4 g carbon, and 9.6 g oxygen. What is the percent by mass of oxygen in the sample?

$$\frac{9.6}{20.0}\times100\%=48\%$$

Q: A mass spectrometer is used to determine the atomic mass of silver, which has two isotopes: $$^{107}\mathrm{Ag} (51.84$$%) and $$^{109}\mathrm{Ag} (48.16$$%). What is the atomic mass of silver?

$$(106.90509\times0.5184)+(108.90476\times0.4816)=107.87\,\mathrm{amu}$$

Q: Calculate the molecular mass of ammonium nitrate ($$\mathrm{NH}_4\mathrm{NO}_3) $$using the atomic masses: N = 14.01 amu, H = 1.008 amu, O = 16.00 amu.

$$(2\times14.01)+(4\times1.008)+(3\times16.00)=80.05\,\mathrm{amu}$$

Question 1

Which of the following best describes a compound?

Accepted Answer

A substance composed of two or more elements that are chemically combined.

Question 2

A student mixes sand and water in a beaker. Which type of mixture is formed, and why?

Accepted Answer

A heterogeneous mixture, because there are visible boundaries between the sand and water.

Question 3

Which separation technique would be most effective for separating a precipitate from a solution?

Accepted Answer

Filtration

Question 4

According to the Law of Mass Conservation, what is the total mass of products formed when 10 g of glucose reacts with 12 g of oxygen to produce carbon dioxide and water?

Accepted Answer

$$10\,+\,12\,=\,22\,\mathrm{g}$$

Question 5

A sample of calcium carbonate contains 8.0 g calcium, 2.4 g carbon, and 9.6 g oxygen. What is the percent by mass of oxygen in the sample?

Accepted Answer

$$\frac{9.6}{20.0}	imes100\%=48\%$$

Question 6

Which statement best illustrates the Law of Multiple Proportions?

Accepted Answer

Carbon forms two oxides, one with twice as much oxygen per gram of carbon as the other.

Question 7

How many neutrons are present in the isotope $$^{30}\mathrm{Si}$$?

Accepted Answer

$$30\,-\,14\,=\,16$$

Question 8

A mass spectrometer is used to determine the atomic mass of silver, which has two isotopes: $$^{107}\mathrm{Ag} (51.84$$%) and $$^{109}\mathrm{Ag} (48.16$$%). What is the atomic mass of silver?

Accepted Answer

$$(106.90509	imes0.5184)+(108.90476	imes0.4816)=107.87\,\mathrm{amu}$$

Question 9

Which of the following elements is a transition metal located in Group 9 and Period 4 of the periodic table?

Accepted Answer

Cobalt (Co)

Question 10

What monatomic ion would calcium (Z = 20) most likely form?

Accepted Answer

$$\mathrm{Ca}^{2+}$$

Question 11

Which of the following is the correct formula for magnesium nitride?

Accepted Answer

$$\mathrm{Mg}_3\mathrm{N}_2$$

Question 12

What is the systematic name for the compound $$\mathrm{Fe}_2\mathrm{O}_3$$?

Accepted Answer

Iron(III) oxide

Question 13

Which of the following is the correct formula for sodium sulfite?

Accepted Answer

$$\mathrm{Na}_2\mathrm{SO}_3$$

Question 14

Which acid is formed when the anion $$\mathrm{Br}^-$$ dissolves in water?

Accepted Answer

Hydrobromic acid ($$\mathrm{HBr})$$

Question 15

What is the correct name for the covalent compound $$\mathrm{N}_2\mathrm{O}_4$$?

Accepted Answer

Dinitrogen tetroxide

Question 16

Calculate the molecular mass of ammonium nitrate ($$\mathrm{NH}_4\mathrm{NO}_3) $$using the atomic masses: N = 14.01 amu, H = 1.008 amu, O = 16.00 amu.

Accepted Answer

$$(2	imes14.01)+(4	imes1.008)+(3	imes16.00)=80.05\,\mathrm{amu}$$

Question 17

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 18

Which of the following is a correct example of a binary acid?

Accepted Answer

Hydrochloric acid ($$\mathrm{HCl})$$

Question 19

A sample contains only one type of particle, each consisting of two different types of atoms bonded together. How should this sample be classified?

Accepted Answer

Compound

Study Notes: Components of Matter and Atomic Theory

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드