Question 1

Water has H at the beginning of its formula, so it is considered to be an acid.

Accepted Answer

Water (H2O) is not considered to be an acid. It has a neutral pH of 7 and is neither acidic (pH<7) nor basic (pH>7). In fact, it can act as a neutralizer or buffer for both acidic and basic substances.

Question 2

When naming binary molecular compounds, it is always unnecessary to use Greek prefixes.

Accepted Answer

Binary molecular compounds consist of two nonmetallic elements and require the use of Greek prefixes to indicate the number of atoms of each element present in the molecule. For example, carbon dioxide is CO2, not carbon oxide.

Question 3

SO₃ and SO₃²⁻ have the same number of each type of atom, so they have the same name and the same chemical properties.

Accepted Answer

The two sequences represent different structures due to the presence of different branching and positioning of functional groups, which can lead to different names and chemical properties despite having the same number of each type of atom.

Question 4

Which of the following best describes HCl when dissolved in water?

Accepted Answer

HCl is a strong acid and therefore when it is dissolved in water, it completely dissociates into H+ ions and Cl- ions, making it a strong electrolyte.

Question 5

Most molecular compounds remain as molecules when dissolved in water.

Accepted Answer

Molecular compounds are composed of two or more non-metal atoms bonded covalently. When dissolved in water, they do not dissociate into ions and remain as individual molecules. Examples of molecular compounds include glucose (C6H12O6), sucrose (C12H22O11), and ethanol (C2H5OH).

Question 6

When a substance dissolves, heat is added to the compound in the solid state, and it is converted to the liquid state. When a substance melts, as in water, the substance becomes surrounded by solvent molecules, and no heat is added.

Accepted Answer

When a substance melts, heat is added to the substance in the solid state to overcome the intermolecular forces and convert it to the liquid state. The surrounding solvent molecules come into play during dissolution, not melting.

Question 7

The central atom is normally listed first in the formula for a binary molecule or ion.

Accepted Answer

The central atom is typically listed first in the formula for a binary molecule or ion to indicate its position in the structure.

Question 8

Polyatomic ions that contain oxygen attached to some other element are called oxoanions.

Accepted Answer

This statement is true, as oxoanions are polyatomic ions made up of a central atom bonded to oxygen atoms and one or more atoms of another element. Examples of oxoanions include sulfate (SO4 2-), nitrate (NO3 -), and phosphate (PO4 3-).

Question 9

Methane, CH₄, and acetic acid, CH₃CO₂H, are both acids because they both contain hydrogen.

Accepted Answer

The answer of Methane, CH₄, and acetic acid, CH₃CO₂H, are...

Question 10

Nonelectrolytes are compounds which break apart into ions when dissolved in water.

Accepted Answer

Nonelectrolytes are compounds that do not break apart into ions when dissolved in water.

Question 11

From their position in the periodic table, we would predict that both oxygen and sulfur would have a charge of 2− in a binary ionic compound.

Accepted Answer

Both oxygen and sulfur are in Group 16 of the periodic table, which means they tend to gain two electrons to achieve a stable electron configuration, resulting in a 2− charge in ionic compounds.

Question 12

A molecular compound is composed of atoms of a metal and a nonmetal.

Accepted Answer

A molecular compound is composed of nonmetal atoms only. Compounds with metal and nonmetal atoms are called ionic compounds.

Question 13

In the old system of naming ionic compounds formed from metals with two different charges, the suffix -ous is used for the higher charge, while the suffix -ic indicates the lower charge.

Accepted Answer

In the old system of naming ionic compounds formed from metals with two different charges, the suffix -ous is used for the lower charge, while the suffix -ic indicates the higher charge.

Quiz 3: Chemical Compounds