Chemistry Chapter: Balancing Chemical Equations

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What does the law of conservation of mass state?

Mass is created during chemical reactions.

Chemical reactions do not involve mass changes.

The total mass of reactants and products is always equal. (correct)

Mass can be destroyed in physical changes.

Why must a chemical equation be balanced?

To indicate that mass has been created in the reaction.

To show that the reaction can proceed without a catalyst.

To demonstrate that the same number of atoms are present on both sides. (correct)

To ensure it accurately represents the reactants only.

In the reaction of sodium with water, what is produced?

Hydrogen gas. (correct)

Sodium hydroxide. (correct)

Baking soda.

Carbon dioxide gas.

What do the reactants and products of a chemical reaction have in common?

They are composed of the same types of atoms. (C) Signup and view all the answers

Which of the following best describes coefficients in a chemical equation?

They represent the amount of each substance in the reaction. (B) Signup and view all the answers

What is the main purpose of balancing a chemical equation?

To ensure the same number of each type of atom is present. (C) Signup and view all the answers

Which of the following scenarios exemplifies the law of conservation of mass?

The total mass of reactants equals the total mass of products. (A) Signup and view all the answers

In the reaction of baking soda with vinegar, what happens to the total mass?

It remains constant when measured correctly. (B) Signup and view all the answers

What is the unbalanced formula equation for the reaction of ammonia with oxygen?

NH3 + O2 → NO + H2O (C) Signup and view all the answers

How many nitrogen atoms are present in the reactants of the unbalanced equation?

1 (B) Signup and view all the answers

What adjustment is made to NH3 in order to balance the hydrogen atoms in the equation?

Add a coefficient of 2 (A) Signup and view all the answers

What is the balanced equation for the reaction of ammonia with oxygen?

2NH3 + O2 → 2NO + 3H2O (D) Signup and view all the answers

How many hydrogen atoms are contained in the product side after balancing the equation?

6 (A) Signup and view all the answers

What is the total number of oxygen atoms on the product side of the balanced equation?

3 (A) Signup and view all the answers

What principle is used to adjust coefficients when applying the odd-even technique?

Multiplying an odd number by 2 always results in an even number. (D) Signup and view all the answers

Which of the following represents a common mistake when balancing the equation NH3 + O2 → NO + H2O?

Adding coefficients without checking balance (C) Signup and view all the answers

What happens to the coefficient for O2 when the equation 4NH3 + 2O2 → 4NO + 6H2O is balanced?

It changes to 5. (A) Signup and view all the answers

Which product is formed when calcium hydroxide reacts with phosphoric acid?

Calcium phosphate (A) Signup and view all the answers

In the balanced equation 4NH3 + 5O2 → 4NO + 6H2O, how many hydrogen atoms are present on each side?

12 hydrogen atoms (C) Signup and view all the answers

In the reaction 1 HgCl2 + AgNO3 → Hg(NO3)2 + AgCl, what type of reaction is occurring?

Double displacement (A) Signup and view all the answers

What is a balanced equation?

An equation that has equal numbers of each type of atom on both sides (B) Signup and view all the answers

Which polyatomic ion does not rearrange during a chemical reaction when balancing an equation?

NO3^- (A) Signup and view all the answers

When balancing the equation 2Fe(OH)2 + H2O2 → 2Fe(OH)3, what remains conserved?

The number of iron atoms (C) Signup and view all the answers

When balancing a chemical equation, what should be adjusted?

The coefficients of the compounds (B) Signup and view all the answers

What is produced alongside mercury when aluminum reacts with mercury(II) acetate?

Al(CH3COO)3 (C) Signup and view all the answers

How many oxygen atoms are present in the equation once it is balanced, as 4NH3 + 5O2 → 4NO + 6H2O?

10 oxygen atoms (B) Signup and view all the answers

Which reaction shows the conversion of ammonium dichromate to chromium oxide?

(NH4)2Cr2O7 → Cr2O3 + N2 + H2O (D) Signup and view all the answers

What is the correct balanced equation for the reaction of acetylene (C2H2) with oxygen?

2C2H2 + 5O2 → 4CO2 + 2H2O (C) Signup and view all the answers

In the reaction 3FeS2 + 6Cl2 → 3FeCl3 + 6S2Cl2, how many chlorine atoms are involved?

12 chlorine atoms (B) Signup and view all the answers

In the equation NH3 + CuO → N2 + Cu + H2O, what happens to the copper?

It is reduced in the reaction. (C) Signup and view all the answers

What is the main reason for utilizing polyatomic ions in balancing chemical equations?

They can be counted as one unit simplifying the balancing process. (D) Signup and view all the answers

Which compound is formed in the reaction Na2SiF6 + Na → Si + NaF?

Sodium fluoride (A) Signup and view all the answers

What is the main purpose of categorizing chemical reactions?

To identify similarities and patterns in reactions (C) Signup and view all the answers

What are the products of the complete combustion of hydrocarbons?

Carbon dioxide and water vapor (A) Signup and view all the answers

Which statement accurately describes combustion reactions?

They produce energy by reacting carbon-based compounds with oxygen. (B) Signup and view all the answers

Which of the following is an example of a hydrocarbon mentioned in the context?

Propane (C) Signup and view all the answers

In combustion reactions, what is typically generated as one of the primary products?

Carbon dioxide (A) Signup and view all the answers

What does the combustion of methane yield?

Carbon dioxide and water vapor (A) Signup and view all the answers

How are hydrocarbons defined in terms of their composition?

They are composed of only carbon and hydrogen. (A) Signup and view all the answers

What is a common use for propane as mentioned?

Fuel for lanterns and stoves (A) Signup and view all the answers

What type of compound is formed when two elements react?

Binary compound (D) Signup and view all the answers

What happens when a metal from Groups 1 and 2 reacts with a nonmetal?

An ionic compound is formed (C) Signup and view all the answers

How can you predict the formula of a compound formed from a metal and a nonmetal?

By using the charges of the ions (C) Signup and view all the answers

What type of reaction is formed when water reacts with a metal oxide from Groups 1 or 2?

Ternary synthesis reaction (D) Signup and view all the answers

What can nonmetals on the far right of the periodic table do when they react with each other?

Form multiple different compounds (C) Signup and view all the answers

Which of the following reactions produces carbonic acid?

CO2 + H2O → H2CO3 (A) Signup and view all the answers

How many electrons do metals in Groups 1 and 2 typically lose?

They lose one and two electrons respectively (B) Signup and view all the answers

What is formed when carbon dioxide combines with water?

Carbonic acid (B) Signup and view all the answers

Study Notes

Chemical Reactions

Chemical reactions involve changes in substances, resulting in new substances with different properties.
Reactants are the starting substances, and products are the resulting substances.
Evidence of a chemical reaction includes changes in color, energy release, formation of gas/precipitate/solid, and a change in odor.

Types of Chemical Reactions

Combustion reactions: involve a substance reacting with oxygen to produce heat and light. Typical products are carbon dioxide and water.
Synthesis reactions: two or more reactants combine to form a single product. Often, elements combine to form compounds.
Decomposition reactions: a single compound breaks down into two or more elements or simpler compounds. Often, energy is needed to initiate the reaction.
Displacement reactions: one element replaces another element in a compound. The displacement depends on the reactivity of elements, as measured by the activity series.
Double displacement reactions: involve an exchange of ions between two compounds, leading to the formation of new compounds, typically resulting in a precipitate, gas, or water.

Balancing Chemical Equations

The law of conservation of mass states matter cannot be created or destroyed in a chemical reaction.
Balanced chemical equations have equal numbers of atoms of each type on both sides of the equation.
Coefficients are used to balance equations; they represent the number of molecules of each substance. Subscripts are not changed.
Balancing involves adjusting the coefficients in front of formulas until the number of atoms of each element is the same on both sides of the equation.

Identifying Chemical Reactions

One reactant indicates a decomposition reaction.
Two reactants (element and compound) usually indicate a displacement reaction.
Two compounds indicate a double displacement reaction
Oxygen and a hydrocarbon indicate a combustion reaction.
One product usually indicates a synthesis reaction.

Activity Series

The activity series lists elements in order of decreasing reactivity.
A more reactive element can displace a less reactive element from its compound in a single replacement reaction.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on the law of conservation of mass and the principles of balancing chemical equations. This quiz covers essential concepts such as reactants, products, and various chemical reactions including sodium with water and ammonia with oxygen. Perfect for chemistry students aiming to solidify their understanding.