Question 1

Which statement best describes the Law of Multiple Proportions as demonstrated by the compounds CO and CO$$_2$$?

Accepted Answer

The masses of oxygen that combine with a fixed mass of carbon are in a simple whole-number ratio.

Question 2

A sample of chlorine contains two isotopes: $$^{35}\mathrm{Cl} (75.8$$%) and $$^{37}\mathrm{Cl} (24.2$$%). What is the average atomic mass of chlorine?

Accepted Answer

$$36.5\ \mathrm{amu}$$

Question 3

Which of the following statements about Dalton’s Atomic Theory is NOT correct according to modern understanding?

Accepted Answer

Atoms of a given element are identical in mass and properties.

Question 4

Which of the following best explains why the atomic mass of carbon is not exactly 12.00 amu?

Accepted Answer

The atomic mass is a weighted average of all naturally occurring isotopes of carbon.

Question 5

How many moles of $$\mathrm{H}_2\mathrm{O}$$ molecules are present in 36.0 g of water?

Accepted Answer

$$2.00$$ moles

Question 6

Which of the following elements is a metalloid?

Accepted Answer

Silicon

Question 7

A neutral atom of magnesium has an atomic number of 12 and a mass number of 24. How many neutrons does it contain?

Accepted Answer

$$12$$

Question 8

Which of the following compounds is ionic?

Accepted Answer

$$\mathrm{NaCl}$$

Question 9

What is the molar mass of ammonium sulfate, $$(\mathrm{NH}_4)_2\mathrm{SO}_4$$?

Accepted Answer

$$132.14\ \mathrm{g/mol}$$

Question 10

Which of the following best describes why metals are good conductors of electricity?

Accepted Answer

They have loosely held valence electrons that can move freely.

Question 11

How many chloride ions are present in 29.2 g of aluminum chloride ($$\mathrm{AlCl}_3$$)? (Molar mass $$= 133.34\ \mathrm{g/mol})$$

Accepted Answer

$$3.96 	imes 10$$^{23}$$

Question 12

Which of the following is the correct name for $$\mathrm{P}_2\mathrm{O}_5$$?

Accepted Answer

Diphosphorus pentoxide

Question 13

Which of the following ions is isoelectronic with neon ($$\mathrm{Ne}$$)?

Accepted Answer

$$\mathrm{Na}^+$$

Question 14

A sample contains $$3.01 	imes 10$$^{23}$$ molecules of $$\mathrm{CO}_2$$. What is the mass of the sample? (Molar mass of $$\mathrm{CO}_2 = 44.01\ \mathrm{g/mol}$$)

Accepted Answer

$$22.0\ \mathrm{g}$$

Question 15

Which of the following best describes the difference between a molecule and an ionic compound?

Accepted Answer

A molecule consists of nonmetals sharing electrons, while an ionic compound consists of metals and nonmetals transferring electrons.

Question 16

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

Accepted Answer

$$\mathrm{Mg}_3(\mathrm{PO}_4)_2$$

Question 17

Which of the following is a property of nonmetals?

Accepted Answer

They are poor conductors of heat and electricity.

Question 18

How many atoms are present in 25.0 g of carbon? (Atomic mass of C = 12.0 g/mol)

Accepted Answer

$$1.26 	imes 10$$^{24}$$

Question 19

Which of the following acids is correctly named?

Accepted Answer

$$\mathrm{H}_2\mathrm{SO}_4 is $$sulfuric acid

Chapter 2 Student Notes

Guida di studio - Domande di pratica

Study guide - Flashcard