Chapter 9, Problem 79E

Interpretation Introduction

(a)

Interpretation:

The terms, strong electrolyte and weak electrolyte are to be distinguished precisely.

Concept introduction:

Solutions of substances in which the ions are the conducting species are called electrolytes. The ionization depends on the nature of the substance. Some substances are more ionized in solution and conduct more electricity. Other substances are ionized to a lesser extent and conduct less electricity. The ability of a solution to conduct electricity depends on the number of ions present in the solution.

Answer to Problem 79E

Strong electrolytes produce more number of ions in the solution and are good conductors of electricity. Weak electrolytes produce less number of ions in the solution and are bad conductors of electricity.

Explanation of Solution

Substances whose solutions are very good conductor of electricity are termed as strong electrolytes. They furnish more number of ions. Substances whose solutions are poor conductors of electricity are termed as weak electrolytes. They produce less number of ions.

Conclusion

Strong electrolytes produce more number of ions in the solution and are good conductors of electricity. Weak electrolytes produce less number of ions in the solution and are bad conductors of electricity.

Interpretation Introduction

(b)

Interpretation:

The terms, electrolyte and nonelectrolyte are to be distinguished precisely.

Concept introduction:

Solutions of substances in which the ions are the conducting species are called electrolytes. The ionization depends on the nature of the substance. Some substances are more ionized in solution and conduct more electricity. Other substances are ionized to a lesser extent and conduct less electricity. The ability of a solution to conduct electricity depends on the number of ions present in the solution.

Answer to Problem 79E

Electrolytes are able to conduct electricity. Nonelectrolytes are unable to conduct electricity.

Explanation of Solution

The substances whose solutions can conduct electricity are termed as electrolytes. The conduction of electricity is due to the presence of ions in the solution. Molecular solids cannot dissociate. Therefore, they cannot furnish ions and do not conduct electricity. Therefore, the substances whose solutions cannot conduct electricity are termed as nonelectrolytes.

Conclusion

Electrolytes are able to conduct electricity. Nonelectrolytes are unable to conduct electricity.

Interpretation Introduction

(c)

Interpretation:

The terms, strong acid and weak acid are to be distinguished precisely.

Concept introduction:

Acids are compounds which release a proton or hydrogen ion when present in a solution. Acids are classified as strong or weak on the basis of extent of their ionization.

Answer to Problem 79E

Strong acids ionize completely. Weak acids ionize partially.

Explanation of Solution

Strong acids undergo complete ionization to produce more number of hydrogen ions in the solution. Weak acids undergo partial ionization and produce less number of hydrogen ions in the solution.

Conclusion

Strong acids ionize completely. Weak acids ionize partially.

Interpretation Introduction

(d)

Interpretation:

The terms, conventional, total ionic, and net ionic equations are to be distinguished precisely.

Concept introduction:

Chemical reactions are represented by chemical equations. In a chemical equation the reactants are represented on the left of the arrow while the products are represented on the right of the arrow.

Answer to Problem 79E

In conventional equations, all the reactants and products are written. In total ionic equation, the reactants and products are present in the form of ions. In net ionic equation, only those ions which undergo a change during the reaction are written.

Explanation of Solution

Conventional equations are those chemical equations in which all the reactants and products are written including their respective state symbols. The total ionic equations are those chemical equations in which all the ionic reactants and ionic products are written in the form of their ions. The net ionic equation is a chemical reaction which describes the exact chemical change occurring during the reaction. The spectator ions present in the total ionic equation, which do not take part in the reaction, are removed to get the net ionic equation.

Conclusion

In conventional equations, all the reactants and products are written. In total ionic equation, the reactants and products are present in the form of ions. In net ionic equation, only those ions which undergo a change during the reaction are written.

Interpretation Introduction

(e)

Interpretation:

The terms, burn and oxidize are to be distinguished precisely.

Concept introduction:

Substances are said to burn when they react with atmospheric oxygen completely to produce carbon dioxide and water. Substances are said to be oxidized when there is an increase in oxidation number and it loses electrons.

Answer to Problem 79E

Burning refers to oxidation in presence of atmospheric oxygen. Oxidizing a substance does not require atmospheric oxygen.

Explanation of Solution

Burning is a reaction in which the substance burns in air to react with atmospheric oxygen. Burning of a substance means oxidation in presence of atmospheric oxygen. Oxidizing a substance means the substance undergoes oxidation to lose electron. Oxidation does not require the presence of oxygen.

Conclusion

Burning refers to oxidation in presence of atmospheric oxygen. Oxidizing a substance does not require atmospheric oxygen.

Interpretation Introduction

(f)

Interpretation:

The terms, ion-combination, precipitation, and molecule-formation reactions are to be distinguished precisely.

Concept introduction:

During a chemical reaction, the composition of the substance undergoes a change. Chemical reactions are represented by chemical equations The chemical reactions can be classified as ion-combination precipitation, and molecule-formation reactions.

Answer to Problem 79E

In ion combination reactions, exchange of cations and anions between reactants takes place to form products. In precipitation reaction, one of the products formed is an insoluble compound. In molecular formation reactions, the exchange of cations and anions between reactants takes place to form a molecular product which does not ionize.

Explanation of Solution

Ion combination reactions are those in which the cation of one reactant reacts with the anion of another reactant to form product. The cations and anions are exchanged in the products. If the product formed is an insoluble compound, the reaction is termed as precipitation reaction. Molecular formation reactions are those ion combination reactions in which one of the product formed is a molecular compound and does not undergo ionization.

Conclusion

In ion combination reactions, exchange of cations and anions between reactants takes place to form products. In precipitation reaction, one of the products formed is an insoluble compound. In molecular formation reactions, the exchange of cations and anions between reactants takes place to form a molecular product which does not ionize.

Interpretation Introduction

(g)

Interpretation:

The terms, molecule-formation and neutralization reactions are to be distinguished precisely.

Concept introduction:

During a chemical reaction, the composition of the substance undergoes a change. Chemical reactions are represented by chemical equations. The chemical reactions can be classified as ion-combination, precipitation, and molecule-formation reactions and neutralization reactions.

Answer to Problem 79E

In molecular formation reactions, the exchange of cations and anions between reactants takes place to form a molecular product which does not ionize. In neutralization reactions, acid and base react together to form salt and water.

Explanation of Solution

Molecular formation reactions are those ion combination reactions in which one of the product formed is a molecular compound and does not undergo ionization. Neutralization reactions are the reaction between acid and base to get the respective salt and water.

Conclusion

In molecular formation reactions, the exchange of cations and anions between reactants takes place to form a molecular product which does not ionize. In neutralization reactions, acid and base react together to form salt and water.

Interpretation Introduction

(h)

Interpretation:

The terms, acid, base and salt are to be distinguished precisely.

Concept introduction:

In neutralization reactions, acid and base react together to form salt and water. Acids are substances which give a proton in solution. Bases are the substances which give hydroxyl ion in the solution.

Answer to Problem 79E

Acids give hydrogen ion in solutions. Bases give hydroxyl ion in solutions. Salts are ionic compounds formed by reaction of an acid with a base.

Explanation of Solution

Acids are substances that give hydrogen ion in solution. They can also be defined as the class of compounds that accept a pair of electrons in electron transfer reactions. Bases are substances that produce hydroxyl ion in solution. They can also be defined as the class of compounds which donate a pair of electrons in electron transfer reactions. Salts are formed during the reaction of an acid and a base. They are usually ionic in nature.

Conclusion

In molecular formation reactions, the exchange of cations and anions between reactants takes place to form a molecular product which does not ionize. In neutralization reactions, acid and base react together to form salt and water.