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?
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What is the coordination number?
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How can you describe the electrical charge of an ionic compound?
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What properties characterize ionic compounds? (Select all that apply)
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The correct chemical formula for the compound formed from K+ and S2− is ______.
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The correct chemical formula for the compound formed from Ca2+ and O2− is ______.
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The correct chemical formula for the compound formed from Na+ and O2− is ______.
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The correct chemical formula for the compound formed from Al3+ and N3− is ______.
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What pairs of elements are likely to form ionic compounds?
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Why do ionic compounds conduct electricity when melted or dissolved in water?
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Why are ionic compounds electrically neutral?
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Which would combine to form an ionic compound? (Select all that apply)
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Why are most ionic substances brittle?
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Explain why molten MgCl₂ conducts electricity while crystalline MgCl₂ does not.
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What is a binary compound?
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What is the net charge of an ionic compound?
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What is formed by the strong attractions among positive and negative ions in an ionic compound?
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What is a crystal lattice?
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In a crystal lattice, each positive ion is surrounded by ______ ions.
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In a crystal lattice, each negative ion is surrounded by ______ ions.
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What is an electrolyte?
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What determines whether an ionic compound can conduct electricity?
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Do ionic compounds conduct electricity in a solid state?
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The formation of ionic compounds from positive ions and negative ions is always endothermic.
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What occurs when the energy released during bond formation is reabsorbed?
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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.
