Chemistry Chapter 7.2 Flashcards

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Questions and Answers

What is an ionic compound?

A compound composed of cations and anions

What is an ionic bond?

The electrostatic forces that hold ions together in ionic compounds

What does a chemical formula show?

Shows the numbers of atoms of each element in the smallest representative unit of a substance

What is a formula unit?

The lowest whole-number ratio of ions in an ionic compound Signup and view all the answers

What is the coordination number?

The number of ions of opposite charge that surround the ion in a crystal Signup and view all the answers

How can you describe the electrical charge of an ionic compound?

Neutral Signup and view all the answers

What properties characterize ionic compounds? (Select all that apply)

They are crystalline solids at room temperature Signup and view all the answers

The correct chemical formula for the compound formed from K+ and S2− is ______.

K2S Signup and view all the answers

The correct chemical formula for the compound formed from Ca2+ and O2− is ______.

CaO Signup and view all the answers

The correct chemical formula for the compound formed from Na+ and O2− is ______.

Na2O Signup and view all the answers

The correct chemical formula for the compound formed from Al3+ and N3− is ______.

AlN Signup and view all the answers

What pairs of elements are likely to form ionic compounds?

Li and Cl; Al and O; I and K Signup and view all the answers

Why do ionic compounds conduct electricity when melted or dissolved in water?

The ions are free to move. Signup and view all the answers

Why are ionic compounds electrically neutral?

The anion and cation cancel each other out. Signup and view all the answers

Which would combine to form an ionic compound? (Select all that apply)

I and K Signup and view all the answers

Why are most ionic substances brittle?

Their network of electrostatic attractions and repulsions forms rigid structures. Signup and view all the answers

Explain why molten MgCl₂ conducts electricity while crystalline MgCl₂ does not.

Ions are free to move in molten MgCl₂. Signup and view all the answers

What is a binary compound?

Compounds that contain only 2 elements. Signup and view all the answers

What is the net charge of an ionic compound?

Zero Signup and view all the answers

What is formed by the strong attractions among positive and negative ions in an ionic compound?

Crystal lattice Signup and view all the answers

What is a crystal lattice?

Three dimensional geometric arrangement of particles. Signup and view all the answers

In a crystal lattice, each positive ion is surrounded by ______ ions.

negative Signup and view all the answers

In a crystal lattice, each negative ion is surrounded by ______ ions.

positive Signup and view all the answers

What is an electrolyte?

An ionic compound whose aqueous solution conducts an electric current. Signup and view all the answers

What determines whether an ionic compound can conduct electricity?

Whether the ions are free to move. Signup and view all the answers

Do ionic compounds conduct electricity in a solid state?

False Signup and view all the answers

The formation of ionic compounds from positive ions and negative ions is always endothermic.

False Signup and view all the answers

What occurs when the energy released during bond formation is reabsorbed?

The bonds holding the positive ions and the negative ions together will break apart. Signup and view all the answers

Study Notes

Ionic Compounds and Bonds

Ionic compounds consist of cations (positively charged ions) and anions (negatively charged ions).
An ionic bond is the electrostatic attraction that holds these ions together.

Chemical Representation

A chemical formula indicates the quantity of each type of atom in the smallest unit of a substance.
A formula unit represents the smallest whole-number ratio of ions present in an ionic compound.

Ionic Properties

Ionic compounds are typically crystalline solids at room temperature and have high melting points.
They can conduct electricity when melted or dissolved in water due to the mobility of ions.

Chemical Formulas of Ionic Compounds

K+ and S2- form K2S.
Ca2+ and O2- combine to form CaO.
Na+ and O2- yield Na2O.
Al3+ and N3- create AlN.
Notable ionic compound formulas: BaCl2 (barium chloride), MgO (magnesium oxide), Li2O (lithium oxide), and CaF2 (calcium fluoride).

Conditions for Ionic Bonding

Likely ionic compounds form between Li and Cl, Al and O, as well as I and K.
Ionic compounds are electrically neutral as the positive and negative charges balance each other.

Conductivity and Brittle Nature

Ionic compounds conduct electricity when melted or dissolved because ions become free to move.
In solid form, ionic compounds do not conduct electricity due to fixed ions constrained by strong forces.
The brittle nature arises from rigid structures formed by the network of electrostatic attractions and repulsions.

Crystal Lattice Structure

Ionic compounds form a crystal lattice, a three-dimensional arrangement where each positive ion is surrounded by negative ions, and vice versa.
The strong ionic attractions lead to the stability and interconnectedness of the lattice.

Electrolytes and Conductivity

Electrolytes are ionic compounds that can conduct electricity when dissolved in water.
The ability of ionic compounds to conduct electricity depends on whether the ions are free to move.

Energy in Ionic Bond Formation

The process of forming ionic compounds from ions is always exothermic, indicating energy is released.
If the energy released during bond formation is reabsorbed, the ionic bonds can break apart.

Special Terminology

Binary compounds consist solely of two elements and are commonly found among ionic substances.
The net charge of an ionic compound is always zero, confirming the balance between cations and anions.

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Description

Test your knowledge of key terms in Chemistry Chapter 7.2 with these flashcards. Learn about ionic compounds, ionic bonds, chemical formulas, and formula units through simple definitions. Perfect for quick review and reinforcement of crucial concepts.