Learn About Ions and Ionic Compounds with Holt Chemistry Concept Review Answers Chapter 5rar

Introduction

Holt Chemistry is a textbook that covers the fundamentals of chemistry for high school students. It includes topics such as matter and energy, atoms and moles, the periodic table, chemical bonding, chemical reactions, stoichiometry, gases, solutions, acids and bases, equilibrium, kinetics, thermodynamics, electrochemistry, nuclear chemistry, organic chemistry, and biochemistry. Each chapter contains key terms, concept review questions, chapter review exercises, and standardized test prep exercises to help students master the material.

Holt Chemistry Concept Review Answers Chapter 5rar

In this article, we will focus on Chapter 5: Ions and Ionic Compounds. This chapter explores how atoms form ions by gaining or losing electrons, how ions bond together to form ionic compounds and salts, and how to name and write formulas for ionic compounds using rules and examples. We will provide answers and explanations for the concept review questions, chapter review exercises, and standardized test prep exercises in this chapter.

Chapter 5: Ions and Ionic Compounds

This chapter covers the following main concepts and objectives:

• Explain how atoms form ions by gaining or losing electrons

• Identify monatomic and polyatomic ions by their names and formulas

• Explain how ions bond together to form ionic compounds and salts

• Describe the properties of ionic compounds and salts

• Write formulas for ionic compounds using oxidation numbers

• Name ionic compounds using rules and examples

Section 5.1: Simple Ions

In this section, we will learn how atoms form ions by gaining or losing electrons. We will also learn how to identify monatomic and polyatomic ions by their names and formulas.

Key Terms

• Ion: An atom or group of atoms that has a positive or negative charge.

• Cation: An ion that has a positive charge because it lost one or more electrons.

• Anion: An ion that has a negative charge because it gained one or more electrons.

• Monatomic ion: An ion that consists of only one atom.

• Polyatomic ion: An ion that consists of two or more atoms covalently bonded together.

Concept Review Questions

• How does an atom become an ion?

Answer: An atom becomes an ion by gaining or losing one or more electrons. This changes the number of electrons in the atom, which affects its charge. An atom that gains electrons becomes an anion, and an atom that loses electrons becomes a cation.

• How does the number of protons in an atom compare to the number of electrons in a neutral atom? In a cation? In an anion?

Answer: The number of protons in an atom is equal to the number of electrons in a neutral atom. This means that the atom has no charge. The number of protons in an atom is greater than the number of electrons in a cation. This means that the atom has a positive charge. The number of protons in an atom is less than the number of electrons in an anion. This means that the atom has a negative charge.

• What is the difference between a monatomic ion and a polyatomic ion?

Answer: A monatomic ion is an ion that consists of only one atom, such as Na+ or Cl-. A polyatomic ion is an ion that consists of two or more atoms covalently bonded together, such as NH4+ or SO4^2-.

• How can you tell if an ion is a cation or an anion by looking at its name or formula?

Answer: You can tell if an ion is a cation or an anion by looking at its name or formula. A cation usually has a name that ends with the word "ion" or the suffix "-ium", such as sodium ion or ammonium. A cation also has a formula that shows a positive charge, such as Na+ or NH4+. An anion usually has a name that ends with the suffix "-ide", "-ate", or "-ite", such as chloride, sulfate, or nitrite. An anion also has a formula that shows a negative charge, such as Cl-, SO4^2-, or NO2^-.

Section 5.2: Ionic Bonding and Salts

In this section, we will learn how ions bond together to form ionic compounds and salts. We will also learn about the properties of ionic compounds and salts.

Key Terms

• Ionic bond: A type of chemical bond that results from the attraction between oppositely charged ions.

• Crystal lattice: A regular, repeating arrangement of ions in a solid.

• Electrolyte: A substance that conducts electricity when dissolved in water or melted.

• Formula unit: The simplest ratio of ions in an ionic compound.

• Lattice energy: The energy required to separate one mole of ions in a crystal lattice.

Concept Review Questions

• What is the main force that holds ions together in an ionic compound?

Answer: The main force that holds ions together in an ionic compound is the electrostatic attraction between oppositely charged ions. This attraction forms ionic bonds between the ions.

• How do the properties of ionic compounds differ from those of molecular compounds?

Answer: Ionic compounds differ from molecular compounds in several ways. Ionic compounds tend to have higher melting and boiling points than molecular compounds, because ionic bonds are stronger than covalent bonds. Ionic compounds also tend to be hard and brittle, because their crystal lattices are rigid and can break when stressed. Ionic compounds also tend to be good conductors of electricity when dissolved in water or melted, because their ions are free to move and carry electric charges. Molecular compounds tend to have lower melting and boiling points than ionic compounds, because covalent bonds are weaker than ionic bonds. Molecular compounds also tend to be soft and flexible, because their molecules are held together by weak intermolecular forces that can bend and stretch. Molecular compounds also tend to be poor conductors of electricity when dissolved in water or melted, because their molecules are neutral and do not carry electric charges.

• What is the difference between a formula unit and a molecule?

A molecule is the smallest unit of a molecular compound that retains its chemical and physical properties, such as H2O or CO2. A formula unit does not represent a discrete entity, but rather an average composition of a large number of ions in a crystal lattice. A molecule represents a specific arrangement of atoms that are covalently bonded together.

• What factors affect the lattice energy of an ionic compound?

Answer: The lattice energy of an ionic compound depends on two factors: the size and the charge of the ions. The smaller the ions are, the closer they can get to each other, and the stronger the attraction between them. The higher the charge of the ions are, the greater the attraction between them. Therefore, the lattice energy increases as the size of the ions decreases and as the charge of the ions increases.

Section 5.3: Names and Formulas of Ionic Compounds

In this section, we will learn how to name and write formulas for ionic compounds using rules and examples. We will also learn how to use oxidation numbers to determine the charge of ions in ionic compounds.

Key Terms

• Binary compound: A compound that consists of only two elements.

• Oxidation number: A number that indicates how many electrons an atom has gained, lost, or shared to become stable.

• Stock system: A system of naming ionic compounds that uses Roman numerals to indicate the charge of cations with variable charges.

• Oxyanion: A polyatomic ion that contains oxygen and another element.

Concept Review Questions

• What are the rules for naming binary ionic compounds?

Answer: The rules for naming binary ionic compounds are as follows:

• Name the cation first, followed by the anion.

• If the cation is a monatomic ion, use its element name. If the cation is a polyatomic ion, use its ion name.

• If the cation has more than one possible charge, use Roman numerals in parentheses to indicate its charge.

• If the anion is a monatomic ion, use its element name with the suffix "-ide". If the anion is a polyatomic ion, use its ion name.

For example, NaCl is named sodium chloride, FeCl3 is named iron(III) chloride, and NH4NO3 is named ammonium nitrate.

• What are the rules for writing formulas for binary ionic compounds?

Answer: The rules for writing formulas for binary ionic compounds are as follows:

• Write the symbols for the cation and the anion.

• Determine the charge of each ion using oxidation numbers or ion names.

• Cross over the charges to balance them out. The charge of one ion becomes the subscript of the other ion. If there is no charge or a zero charge, do not write anything.

• Simplify the subscripts by dividing them by their greatest common factor. If there is only one atom of an element, do not write 1 as a subscript.

• Use parentheses around polyatomic ions if there is more than one of them in the formula.

For example, sodium chloride has a formula of NaCl, iron(III) chloride has a formula of FeCl3, and ammonium nitrate has a formula of NH4NO3.

• What are some common oxyanions and how are they named?

Answer: Some common oxyanions and their names are as follows:

Formula Name --- --- NO3^- nitrate NO2^- nitrite SO4^2- sulfate SO3^2- sulfite PO4^3- phosphate PO3^3- phosphite CO3^2- carbonate ClO4^- perchlorate ClO3^- chlorate ClO2^- chlorite ClO^- hypochlorite The names of oxyanions are based on the number of oxygen atoms in the ion. The suffix "-ate" is used for the most common or highest number of oxygen atoms, and the suffix "-ite" is used for one less oxygen atom. The prefix "per-" is used for one more oxygen atom than the "-ate" ion, and the prefix "hypo-" is used for one less oxygen atom than the "-ite" ion.

Chapter Review Exercises

In this section, we will provide answers and explanations for the chapter review exercises in this chapter.

• What is the charge of a magnesium ion?

Answer: The charge of a magnesium ion is 2+. This is because magnesium has an atomic number of 12, which means it has 12 protons and 12 electrons in a neutral atom. To become stable, magnesium loses two electrons to achieve a noble gas configuration. This results in a cation with 12 protons and 10 electrons, which has a charge of 2+.

• What is the name of the polyatomic ion NH4^+?

Answer: The name of the polyatomic ion NH4^+ is ammonium. This is because it consists of one nitrogen atom and four hydrogen atoms covalently bonded together, with a positive charge.

• What is the formula for calcium nitrate?

Answer: The formula for calcium nitrate is Ca(NO3)2. This is because calcium has a charge of 2+, and nitrate has a charge of 1-. To balance the charges, we need two nitrates for every calcium. We use parentheses around the nitrate to indicate that there are two of them in the formula.

• What is the name of the ionic compound Fe2O3?

Answer: The name of the ionic compound Fe2O3 is iron(III) oxide. This is because iron has a charge of 3+, and oxide has a charge of 2-. To indicate the charge of iron, we use Roman numerals in parentheses after its name. We also use the suffix "-ide" for the oxide anion.

• What type of bond forms between sodium and chlorine?

Answer: The type of bond that forms between sodium and chlorine is an ionic bond. This is because sodium is a metal and chlorine is a nonmetal, and they have different electronegativities. Sodium tends to lose one electron to become a cation, and chlorine tends to gain one electron to become an anion. The electrostatic attraction between these oppositely charged ions forms an ionic bond.

Standardized Test Prep Exercises

In this section, we will provide answers and explanations for the standardized test prep exercises in this chapter.

• Which of the following statements is true about ionic compounds?

• They are composed of molecules.

• They have low melting and boiling points.

• They are good conductors of electricity when solid.

• They form crystal lattices when solid.

Answer: D. They form crystal lattices when solid.

Explanation: Ionic compounds are composed of ions, not molecules. They have high melting and boiling points, because ionic bonds are strong and require a lot of energy to break. They are poor conductors of electricity when solid, because their ions are fixed in place and cannot move. They form crystal lattices when solid, because their ions arrange themselves in a regular, repeating pattern.

• What is the correct name for the compound CuCl2?

• Copper chloride

• Copper(II) chloride

• Copper(I) chloride

• Cupric chloride

Answer: B. Copper(II) chloride

Explanation: Copper can have more than one possible charge, so we need to use Roman numerals to indicate its charge in the compound. Since chlorine has a charge of 1-, we can infer that copper has a charge of 2+ in this compound. Therefore, we use (II) after copper's name. The other options are incorrect because they either do not indicate copper's charge or use an outdated naming system.

• What is the correct formula for aluminum sulfate?

• AIS

• Al2(SO4)3

• Al2SO4

• AlSO4

Answer: B. Al2(SO4)3

Explanation: Aluminum has a charge of 3+, and sulfate has a charge of 2-. To balance the charges, we need two sulfates for every aluminum. We use parentheses around the sulfate to indicate that there are two of them in the formula. The other options are incorrect because they either do not balance the charges or do not use parentheses correctly.

• What is the oxidation number of nitrogen in NO3^-?

• -3

• -1

• +1

• +5

Answer: D. +5

Explanation: The oxidation number of an atom is the number of electrons it has gained, lost, or shared to become stable. In a polyatomic ion, the sum of the oxidation numbers of all the atoms must equal the charge of the ion. Oxygen has an oxidation number of -2, and there are three oxygen atoms in NO3^-. Therefore, the sum of the oxidation numbers of oxygen is -6. To make the sum equal to -1, which is the charge of NO3^-, nitrogen must have an oxidation number of +5.

• Which of the following compounds is most likely to be soluble in water?

• PbCl2

• MgO

• KBr

• C6H12O6

Answer: C. KBr

Explanation: A compound is most likely to be soluble in water if it is ionic or polar. Ionic compounds are composed of oppositely charged ions that can interact with the polar water molecules. Polar compounds are composed of molecules that have uneven distribution of electric charges that can also interact with the polar water molecules. KBr is an ionic compound that dissolves in water to form K+ and Br- ions. PbCl2 and MgO are also ionic compounds, but they are insoluble in water because their ions are too strongly attracted to each other to separate. C6H12O6 is a molecular compound that is polar, but it is not very soluble in water because it has a large nonpolar region that does not interact well with water.

Conclusion

In this article, we have learned about Chapter 5: Ions and Ionic Compounds from Holt Chemistry. We have covered how atoms form ions by gaining or losing electrons, how ions bond together to form ionic compounds and salts, and how to name and write formulas for ionic compounds using rules and examples. We have also provided answers and explanations for the concept review questions, chapter review exercises, and standardized test prep exercises in this chapter. We hope that this article has helped you understand and master this topic.

FAQs

Here are some common questions and answers related to this topic:

• What is the difference between an ion and an atom?

Answer: An ion is an atom that has a positive or negative charge because it has gained or lost one or more electrons. An atom is the smallest unit of an element that retains its identity and properties.

• What are some examples of ionic compounds and their uses?

Answer: Some examples of ionic compounds and their uses are as follows:

• Ionic Compound Use --- --- NaCl Table salt, food seasoning, preservative CaCO3 Limestone, marble, chalk, antacid NaHCO3 Baking soda, leavening agent, cleaning agent NH4NO3 Ammonium nitrate, fertilizer, explosive AgNO3 Silver nitrate, photography, disinfectant How can you predict if an ionic compound will form between two elements?

Answer: You can predict if an ionic compound will form between two elements by looking at their electronegativities. Electronegativity is a measure of how strongly an atom attracts electrons. If the difference in electronegativity between two elements is greater than 1.7, they are likely to form an ionic compound. This is because the more electronegative element will take electrons from the less electronegative element, resulting in ions. If the difference in electronegativity between two elements is less than 1.7, they are likely to form a covalent compound. This is because the elements will share electrons more or less equally, resulting in molecules.

• What are some properties of salts?

Answer: Salts are a type of ionic compound that form when an acid reacts with a base. Some properties of salts are as follows:

• They have high melting and boiling points.

• They are hard and brittle.

• They are good conductors of electricity when dissolved in water or melted.

• They have a neutral pH when dissolved in water.

• They can have different colors depending on the ions they contain.

• What is the difference between a formula unit and a mole?

Answer: A formula unit is the simplest ratio of ions in an ionic compound, such as NaCl or MgO. A mole is a unit of measurement that represents 6.02 x 10^23 particles of a substance, such as atoms, molecules, or ions. One mole of an ionic compound contains 6.02 x 10^23 formula units of that compound.

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