Chemistry Chapter on Reactions and Equations

Questions and Answers

List the four observations that indicate that a chemical reaction may have taken place.

Chemical produced, energy change (light or heat), formation of precipitant, color change.

List the three requirements for a correctly written chemical equation.

Represent known facts, have correct symbols and formulas, satisfy the law of conservation of mass.

What is meant by the term coefficient in a chemical equation?

How much the compound is being used in the reaction.

What is an aqueous solution?

Solution that's dissolved in water. Signup and view all the answers

What is a catalyst?

Helps speed up reaction. Signup and view all the answers

What is a reversible reaction?

A chemical reaction in which the products reform the original reactants. Signup and view all the answers

What are the four guidelines useful in balancing an equation?

Identify names of reactants and products, write formula equation by substituting correct formulas for the names of the reactants in the products, balance the equation, count atoms to make sure it is balanced. Signup and view all the answers

What does 'synthesis' refer to in chemistry?

A + B = AB. Signup and view all the answers

What does 'decomposition' refer to in chemistry?

AB = A + B. Signup and view all the answers

What does 'single replacement' refer to in chemistry?

AB + C = CB + A. Signup and view all the answers

What does 'double replacement' refer to in chemistry?

AB + CD = CB + AD. Signup and view all the answers

What does 'combustion' refer to in chemistry?

A + O2 = AO2. Signup and view all the answers

How are most decomposition reactions initiated?

Energy in the form of heat or electricity is added. Signup and view all the answers

A substance is decomposed by an electric current, what is the name of this type of reaction?

Electrolysis. Signup and view all the answers

In what environment do many single replacement reactions commonly occur?

Aqueous solutions. Signup and view all the answers

What is meant by the activity of an element?

A greater activity means a greater ease of loss of electrons to form positive ions. Signup and view all the answers

What is an activity series?

A list of elements organized according to the ease with which the elements undergo certain chemical reactions. Signup and view all the answers

What is the basis in ordering of the elements on the activity series?

Determined by single replacement reactions. Signup and view all the answers

What chemical principle is the basis for the activity series of metals?

Reactivity. Signup and view all the answers

Study Notes

Observations of Chemical Reactions

Indicators of a chemical reaction include the production of a gas, energy changes (light or heat), formation of a precipitate, and color change.

Correctly Written Chemical Equations

A correct chemical equation must represent known facts, utilize appropriate symbols and formulas, and adhere to the law of conservation of mass.

Coefficients in Chemical Equations

Coefficients indicate the number of units of a compound participating in a chemical reaction.

Aqueous Solutions

An aqueous solution is one where a substance is dissolved in water.

Catalysts

Catalysts are substances that accelerate chemical reactions without being consumed in the process.

Reversible Reactions

A reversible reaction allows the products to react and reform the original reactants.

Guidelines for Balancing Equations

To balance a chemical equation, identify the names of reactants and products, write the formula equation, balance the equation, and verify the count of each type of atom.

Types of Reactions

Synthesis: Combination of two reactants to form one product (A + B → AB).
Decomposition: One reactant breaks down into two products (AB → A + B).
Single Replacement: One element replaces another in a compound (AB + C → CB + A).
Double Replacement: Exchange of elements between two compounds (AB + CD → CB + AD).
Combustion: Reaction of a substance with oxygen, typically producing heat and light (A + O₂ → AO₂).

Initiation of Decomposition Reactions

Decomposition reactions are often initiated by applying energy in the form of heat or electricity.

Electrolysis

Decomposition by an electric current is referred to as electrolysis.

Environments for Single Replacement Reactions

Many single replacement reactions occur in aqueous solutions, where the reactants are dissolved in water.

Activity of Elements

An element's activity reflects its tendency to lose electrons easily, forming positive ions.

Activity Series

The activity series ranks elements based on their reactivity, particularly in single replacement reactions.

Basis of the Activity Series

The elements in the activity series are organized primarily based on their outcomes in single replacement reactions.

Principle Behind the Activity Series of Metals

The reactivity of metals serves as the fundamental principle for ranking elements in the activity series.

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Description

Test your knowledge of chemical reactions and equations with this quiz. Topics include identifying indicators of reactions, writing balanced equations, and understanding the role of catalysts and coefficients. Perfect for students looking to reinforce their chemistry concepts!