Question 1

Which of the following statements best explains why water (H$$_2O) is $$considered a compound and not a mixture?

Accepted Answer

Water molecules always have a fixed ratio of two hydrogen atoms to one oxygen atom.

Question 2

Which type of chemical bond is formed when electrons are transferred from one atom to another, resulting in the formation of cations and anions?

Accepted Answer

Ionic bond

Question 3

What is the empirical formula for a compound with the molecular formula C$$_4H$_8O$_4$$?

Accepted Answer

CH$$_2O$$

Question 4

Which of the following best describes the difference between an empirical formula and a molecular formula?

Accepted Answer

An empirical formula shows the simplest whole-number ratio of atoms, while a molecular formula shows the actual number of atoms of each element.

Question 5

Which of the following compounds contains a type two cation and is named using a Roman numeral?

Accepted Answer

FeCl$$_3$$

Question 6

A sample of a compound contains 24.5 g of nitrogen and 70.0 g of oxygen. What is the empirical formula of the compound? (Atomic masses: N = 14.01 g/mol, O = 16.00 g/mol)

Accepted Answer

N$$_2O$_5$$

Question 7

Which of the following best explains why ionic solids, such as NaCl, do not conduct electricity in the solid state but do when dissolved in water?

Accepted Answer

Ions are locked in place in the solid state but are free to move when dissolved.

Question 8

Which of the following is the correct name for the compound P$$_2O$_5$$?

Accepted Answer

Diphosphorus pentoxide

Question 9

Calculate the mass percent of chlorine in C$$_2Cl$_4 ($$tetrachloroethene). (Atomic masses: C = 12.01 g/mol, Cl = 35.45 g/mol)

Accepted Answer

84.8%

Question 10

Which of the following statements about the octet rule is most accurate?

Accepted Answer

Atoms form bonds to lower their potential energy, and the octet rule helps predict when this will occur.

Question 11

What is the formula for the ionic compound formed between magnesium and nitrogen?

Accepted Answer

Mg$$_3N$_2$$

Question 12

Which of the following best describes a polyatomic ion?

Accepted Answer

A group of atoms with a net charge

Question 13

A 325 mg aspirin tablet contains acetylsalicylic acid (C$$_9H$_8O$_4). $$How many molecules of acetylsalicylic acid are in the tablet? (Molar mass = 180.16 g/mol, Avogadro's number = $$6.022 	imes 10$$^{23}$$)

Accepted Answer

$$1.09 	imes 10$$^{21}$$

Question 14

Which of the following is the correct Lewis symbol for silicon (Si)?

Accepted Answer

A Si atom with four dots around it

Question 15

Which of the following best explains why MgO has a higher melting point than NaCl?

Accepted Answer

MgO has ions with larger charges, leading to stronger electrostatic attraction.

Question 16

Which of the following is the correct name for the compound FeS?

Accepted Answer

Iron(II) sulfide

Question 17

A compound has an empirical formula of CH$$_2O $$and a molar mass of 180 g/mol. What is its molecular formula?

Accepted Answer

C$$_6H$_{12}O$_6$$

Question 18

Which of the following is a correct ratio derived from the molecular formula for water (H$$_2O$$)?

Accepted Answer

2 mol H : 1 mol O

Question 19

Which of the following best describes the structure of an ionic solid such as NaCl?

Accepted Answer

A regular three-dimensional array of alternating cations and anions

Question 20

Which of the following is the correct formula for the compound formed between aluminum and nitrogen?

Accepted Answer

Al$$_3N$_2$$

Chapter 4: Molecules and Compounds – Structure, Bonding, and Chemical Formulas

Guida di studio - Domande di pratica

Study guide - Flashcard