6. Chemical Quantities & Aqueous Reactions

Molecular Equations

Writing Chemical Equations in Words

Predict the products and write a balanced molecular equation
for each reaction. If no reaction occurs, write “NO REACTION.”
d. aqueous ammonium chloride and aqueous calcium
hydroxide

Fe(C2H3O2)3

 Acetate compounds are soluble in water. 

 This is not an exception to the solubility of chlorides in water. 

Correct, Pb2+ is an exception in the solubility rule involving sulfates.

 According to the solubility rules, one of these compounds is an exception. 

 In general, a compound is termed soluble if it dissolves in water and insoluble if it does not.  Refer to the solubility rules. 

 Which of the following compounds is insoluble in water? 

Write a molecular equation for the precipitation reaction that
occurs (if any) when each pair of aqueous solutions is mixed. If
no reaction occurs, write “NO REACTION.”
a. potassium carbonate and lead(II) nitrate

Writing Molecular, Total & Net Ionic Equations

Balance the following equations and indicate whether
they are combination, decomposition, or combustion
reactions:
(b) Li3N1s2 + BN1s2 ¡Li3BN21s2

Write a balanced chemical equation for the reaction that
occurs when (a) Mg(s) reacts with Cl21g2

Which of the following solutions will not form a precipitate when added to 0.10 M NaOH?
(a) 0.10 M MgBr2
(b) 0.10 M NH4Br
(c) 0.10 M FeCl2

Write a balanced equation for the reaction that occurs in
each of the following cases: (a) Lithium is added to water.

Which of the following solutions will not form a precipitate when added to 10 mL of 0.10 M KOH? (LO 4.10, 4.11)
(a) 10 mL of 0.10 NH4Cl 
(b) 10 mL of 0.10 M PbSO4 
(c) 10 mL of 0.10 M Fe(NO3)3 
(d) 10 mL of 0.10 M AgCH3CO2

Which of the following solutions will not form a precipitate when added to 0.10 M BaCl2?
(a) 0.10 M LiNO3 
(b) 0.10 M K2SO4 
(c) 0.10 M AgNO3

Balance the following equations and indicate whether
they are combination, decomposition, or combustion
reactions:
(a) C7H161s2 + O21g2 ¡CO21g2 + H2O1l2

Separate samples of a solution of an unknown ionic compound
are treated with dilute AgNO3, Pb1NO322, and BaCl2.
Precipitates form in all three cases. Which of the following
could be the anion of the unknown salt: Br-, CO32-, NO3-?

Identify the precipitate (if any) that forms when the following
solutions are mixed, and write a balanced equation for
each reaction.(b) LiOH and MnCl2

(a) When chlorine atoms react with atmospheric ozone, what are the products of the reaction?

Write a molecular equation for the precipitation reaction that
occurs (if any) when each pair of aqueous solutions is mixed. If
no reaction occurs, write “NO REACTION.”
c. copper(II) nitrate and magnesium sulfide

A hydrochloric acid solution will neutralize a sodium hydroxide
solution. Look at the molecular views showing one beaker of
HCl and four beakers of NaOH. Which NaOH beaker will just
neutralize the HCl beaker? Begin by writing a balanced chemical
equation for the neutralization reaction.
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/10a3324171838752-1659950315549.jpg" alt="" />

You are presented with a white solid and told that due to
careless labeling it is not clear if the substance is barium
chloride, lead chloride, or zinc chloride. When you transfer
the solid to a beaker and add water, the solid dissolves to
give a clear solution. Next an Na2SO41aq2 solution is added
and a white precipitate forms. What is the identity of the unknown
white solid?

Complete and balance each acid–base equation.
c. H2SO4(aq) + NaOH(aq)¡

Assume that an aqueous solution of OH-, represented as a blue sphere, is allowed to mix with a solution of an acid HnA, represented as a red sphere. Three possible outcomes are depicted by boxes (1)–(3), where the green spheres represent An-, the anion of the acid: 
Which outcome corresponds to each of the following reactions? 
(a) 
(b) 
(c)

Classify each of the following reactions as a precipitation, acid–base neutralization, or oxidation–reduction. 
(a) 
(b) 
(c)

Acetylene 1C2H22 and nitrogen 1N22 both contain a triple
bond, but they differ greatly in their chemical properties.
(c) Write balanced chemical equations for the complete
oxidation of N2 to form N2O51g2 and of acetylene to form
CO21g2 and H2O1g2.

Write a balanced chemical equation for the complete oxidation of acetylene to form CO2( g) and H2O(g).

Suggest how the cations in each of the following solution 
mixtures can be separated: (c) Pb2 + and Al3 +.

Complete and balance each equation. If no reaction occurs, 
write “NO REACTION.” 
c. CrBr2(aq) + Na2CO3(aq)¡

The following three solutions are mixed: 100.0 mL of 0.100 M Na2SO4, 50.0 mL of 0.300 M ZnCl2, and 100.0 mL of 0.200 M Ba(CN)2. 
(a) What ionic compounds will precipitate out of solution?

Molecular Equations Example 2

Write balanced ionic equations for the following reactions.
(a) Aqueous perchloric acid is neutralized by aqueous calcium hydroxide.

Assume that you have an aqueous mixture of NaNO3 and AgNO3. How could you use a precipitation reaction to separate the two metal ions?

Write a balanced chemical equation for the reaction that occurs
when (a) titanium metal reacts with O21g2

Ionic vs. Molecular

Balance the following equations and indicate whether
they are combination, decomposition, or combustion
reactions:
(a) NaClO31s2¡NaCl1s2 + O2(g)

Assume that you have an aqueous solution of an unknown salt. Treatment of the solution with dilute NaOH, Na2SO4, and KCl produces no precipitate. Which of the following cations might the solution contain?
(a) Ag+
(b) Cs+
(c) Ba2+
(d) NH4 +

How would you prepare the following substances by a precipitation reaction?
(a) PbSO4

Molecular, Complete Ionic, and Net Ionic Equations

Complete and balance each equation. If no reaction occurs,
write “NO REACTION.”
b. KCl(aq) + CaS(aq)¡

Trifluoroacetic acid has the chemical formula CF3CO2H. 
It is a colorless liquid that has a density of 1.489 g/mL. 
(b) Trifluoroacetic acid can react with NaOH in aqueous 
solution to produce the trifluoroacetate ion, CF3COO2. 
Write the balanced chemical equation for this reaction.

A solution of 105.0 mL of 0.300 M NaOH is mixed with a
solution of 150.0 mL of 0.060 M AlCl3. (a) Write the balanced 
chemical equation for the reaction that occurs.

A compound with the formula XOCl2 reacts with water, yielding HCl and another acid H2XO3, which has two acidic hydrogens that react with NaOH. When 0.350 g of XOCl2 was added to 50.0 mL of water and the resultant solution was titrated, 96.1 mL of 0.1225 M NaOH was required to react with all the acid.
(a) Write a balanced equation for the reaction of XOCl2 with H2O.

Balanced Molecular Equation

Complete Ionic &  Net Ionic Equations

Predict whether a chemical reaction occurs and write the balanced molecular equation.Ag2SO4 (aq) + KCl (aq) →

Molecular, Ionic, and Net Ionic Equations

Write a balanced equation for the reaction that occurs in
each of the following cases: (c) Hydrogen bromide gas reacts with chlorine gas.

How could you use a precipitation reaction to separate each of the following pairs of anions? Write the formula for each reactant you would add, and write a balanced net ionic equation for each reaction.
(a)

Assume that an aqueous solution of a cation, represented as a red sphere, is allowed to mix with a solution of an anion, represented as a yellow sphere. Three possible outcomes are represented by boxes (1)–(3): <img src="https://lightcat-files.s3.amazonaws.com/problem_images/09a924224806fc84-1675347547059.jpg" alt="" />
Which outcome corresponds to each of the following reactions?
(a) 2 Na+(aq) + CO32-(aq) S
(b) Ba2+(aq) + CrO42-(aq) S
(c) 2 Ag+(aq) + SO32-(aq) S

You know that an unlabeled bottle contains an aqueous solution
of one of the following: AgNO3, CaCl2, or Al21SO423. A
friend suggests that you test a portion of the solution with
Ba1NO322 and then with NaCl solutions. According to your
friend’s logic, which of these chemical reactions could occur,
thus helping you identify the solution in the bottle?
(a) Barium sulfate could precipitate. (b) Silver chloride
could precipitate. (c) Silver sulfate could precipitate.
(d) More than one, but not all, of the reactions described in
answers a–c could occur. (e) All three reactions described in
answers a–c could occur.

A 25.0-mL sample of 0.050 M barium nitrate solution was 
mixed with 25.0 mL of 0.050 M sodium sulfate solution 
labeled with radioactive sulfur-35. The activity of the initial 
sodium sulfate solution was 1.22 * 106 Bq>mL. After the 
resultant precipitate was removed by filtration, the remaining 
filtrate was found to have an activity of 250 Bq/mL. 
(a) Write a balanced chemical equation for the reaction 
that occurred.

Write a balanced equation for the reaction that occurs in
each of the following cases: (c) A fresh surface of lithium metal is exposed to oxygen gas.

Complete and balance each equation. If no reaction occurs,
write “NO REACTION.”
a. NaNO3(aq) + KCl(aq)¡

Write a balanced equation for the reaction that occurs in
each of the following cases: (c) Potassium reacts with chlorine gas.

Three cations, Ni2 + , Cu2 + , and Ag+, are separated using
two different precipitating agents. Based on Figure 17.23,
what two precipitating agents could be used? Using these
agents, indicate which of the cations is A, which is B, and
which is C.

In a typical molecular equation, two reactants dissociate and reorganize to form new products.&nbsp;

Determine the balanced equation for the neutralization equationCa(OH)2 (aq) + HCN (aq) →

A solution of 105.0 mL of 0.300 M NaOH is mixed with a
solution of 150.0 mL of 0.060 M AlCl3. (b) What
precipitate forms?

Complete and balance each equation. If no reaction occurs,
write “NO REACTION.”
a. LiI(aq) + BaS(aq)

"In the course of various qualitative analysis procedures, the 
following mixtures are encountered: (d) Ag+ and Mn2 + . Suggest how each mixture might be separated."

Complete and balance each acid–base equation. 
b. HC2H3O2(aq) + Ca(OH)2(aq)¡

Assume that you have an aqueous solution of an unknown salt. Treatment of the solution with dilute BaCl2, AgNO3, and Cu(NO3)2 produces no precipitate. Which of the following anions might the solution contain?
(a) Cl-
(b) NO3 
(c) OH-
(d) SO4- 2-

Write a balanced equation for the reaction that occurs in
each of the following cases: (d) Aluminum
trichloride reacts with aqueous sodium hydroxide.

Will precipitation occur when the following solutions are 
mixed? If so, write a balanced chemical equation for the reaction. 
(c) Na2S and FeCl3.

Natural gas consists primarily of methane, CH4(g). (b) Write a balanced chemical equation for the incomplete combustion of methane to product CO(g) as the only carbon-containg product.

Predict the products and write a balanced molecular equation
for each reaction. If no reaction occurs, write “NO REACTION.”
a. HCl(aq) + Hg2(NO3)2(aq)¡

A reaction occurs only if solid, gas or liquid water is formed. If both products are aqueous, NO REACTION has occurred.

Write balanced chemical equations for (c) the combination reaction between 
sulphur dioxide gas and liquid water to produce sulfurous 
acid.

A solution containing several metal ions is treated with dilute 
HCl; no precipitate forms. The pH is adjusted to about 
1, and H2S is bubbled through. Again, no precipitate forms. 
The pH of the solution is then adjusted to about 8. Again, 
H2S is bubbled through. This time a precipitate forms. The 
filtrate from this solution is treated with 1NH422HPO4. No 
precipitate forms. Which of these metal cations are either 
possibly present or definitely absent: Al3 +, Na +, Ag +, Mg2 +?

Write balanced ionic equations for the following reactions.
(b) Aqueous sodium hydroxide is neutralized by aqueous acetic acid.

Uranium hexafluoride, UF6, is processed to produce fuel for
nuclear reactors and nuclear weapons. UF6 can be produced
in a two-step reaction. Solid uranium (IV) oxide, UO2, is first
made to react with hydrofluoric acid (HF) solution to form
solid UF4 with water as a by-product. UF4 further reacts with
fluorine gas to form UF6.
(b) Which step is an acid-base reaction?

Assume that you have an aqueous mixture of BaCl2 and CuCl2. How could you use a precipitation reaction to sepa-rate the two metal ions?

How could you use a precipitation reaction to separate each of the following pairs of cations? Write the formula for each reactant you would add, and write a balanced net ionic equation for each reaction.
(a)

What kind of reaction is the “water-splitting” reaction?
H2O(l)¡H2(g) + ½ O2(g)
(a) an acid-base reaction
(b) a metathesis reaction
(c) a redox reaction
(d) a precipitation reaction

Write a balanced equation for the reaction that occurs in
each of the following cases: (a) Potassium metal is exposed to
an atmosphere of chlorine gas.

Three solutions are mixed together to form a single solution; 
in the final solution, there are 0.2 mol Pb1CH3COO)2, 
0.1 mol Na2S, and 0.1 mol CaCl2 present. What solid(s) will 
precipitate?

Write balanced ionic equations for the following reactions.
(b) Aqueous barium hydroxide is neutralized by aqueous nitric acid.

Write a molecular equation for the precipitation reaction that
occurs (if any) when each pair of aqueous solutions is mixed. If
no reaction occurs, write “NO REACTION.”
a. sodium chloride and lead(II) acetate
b. potassium sulfate and strontium iodide
c. cesium chloride and calcium sulfide
d. chromium(III) nitrate and sodium phosphate

Complete and balance each equation. If no reaction occurs, 
write “NO REACTION.” 
d. NH4Cl(aq) + AgNO3(aq)¡

Write balanced ionic equations for the following reactions.
(a) Aqueous hydrobromic acid is neutralized by aqueous calcium hydroxide.

Baking soda (sodium bicarbonate, NaHCO3) reacts with 
acids in foods to form carbonic acid 1H2CO32, which in 
turn decomposes to water and carbon dioxide gas. In a
cake batter, the CO21g2 forms bubbles and causes the cake 
to rise. (a) A rule of thumb in baking is that 1/2 teaspoon of 
baking soda is neutralized by one cup of sour milk. The acid 
component in sour milk is lactic acid, CH3CH1OH2COOH. 
Write the chemical equation for this neutralization reaction.

Assume that an aqueous solution of a cation, represented as a blue sphere, is allowed to mix with a solution of an anion, repre-sented as a red sphere, and that the following result is obtained: 
Which combinations of cation and anion, chosen from the fol-lowing lists, are compatible with the observed results? Explain
Cations: Na+, Ca2+, Ag+, Ni2+ 
Anions: Cl-, CO3
2-, CrO4 2-, NO3

Predict whether a chemical reaction occurs and write the balanced molecular equation.MgBr2 (aq) + &nbsp;NaC2H3O2 (aq) →

A 250.0 g sample of a white solid is known to be a mixture of KNO3, BaCl2, and NaCl. When 100.0 g of this mixture is dis-solved in water and allowed to react with excess H2SO4, 67.3 g of a white precipitate is collected. When the remaining 150.0 g of the mixture is dissolved in water and allowed to react with excess AgNO3, 197.6 g of a second precipitate is collected. 
(a) What are the formulas of the two precipitates?

A solution contains one or more of the following ions: Hg2
2 + ,
Ba2 + , and Fe2 + . When you add potassium chloride to the solution,
a precipitate forms. The precipitate is filtered off, and you
add potassium sulfate to the remaining solution, producing no
precipitate. When you add potassium carbonate to the remaining
solution, a precipitate forms. Which ions were present in
the original solution?

(a) Write a balanced equation for the reaction of potassium metal with water.

Predict the products and write a balanced molecular equation
for each reaction. If no reaction occurs, write “NO REACTION.”
b. Cr(NO3)3(aq) + LiOH(aq)¡

Magnesium ions are removed in water treatment by the addition of slaked lime, Ca(OH)2. Write a balanced chemical equation to describe what occurs in this process

Molecular Equations Example 1

In the course of various qualitative analysis procedures, the 
following mixtures are encountered: (a) Zn2 + and Cd2 + . Suggest how each mixture might be separated.

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Clutch Prep

1. Intro to General Chemistry

2. Atoms & Elements

3. Chemical Reactions

4. BONUS: Lab Techniques and Procedures

5. BONUS: Mathematical Operations and Functions

7. Gases

8. Thermochemistry

9. Quantum Mechanics

10. Periodic Properties of the Elements

11. Bonding & Molecular Structure

12. Molecular Shapes & Valence Bond Theory

13. Liquids, Solids & Intermolecular Forces

14. Solutions

15. Chemical Kinetics

16. Chemical Equilibrium

17. Acid and Base Equilibrium

18. Aqueous Equilibrium

19. Chemical Thermodynamics

20. Electrochemistry

21. Nuclear Chemistry

22. Organic Chemistry

23. Chemistry of the Nonmetals

24. Transition Metals and Coordination Compounds

[BOOK CHEM] Clutch Version

Solutions

Solutions represent homogeneous mixtures made of 2 or more components that form a uniform composition.&nbsp;

Osmolarity

Osmolarity (ionic molarity) represents the number of moles of ions per liter of solution.&nbsp;

Gas Evolution Equations

A Gas Evolution Equation is a molecular equation that involves the creation of specific gases.&nbsp;

Molecular Equations show reacting molecules involved in a chemical reaction.&nbsp;

Complete Ionic Equations

Complete Ionic Equations show aqueous compounds as fully dissociated ions.&nbsp;

Solubility Rules

The Solubility Rules are a convenient set of guidelines to help us determine if a compound will be soluble or insoluble.

Molarity

Ever wonder how a mass amount such as moles can be converted into the volume amount of liters? Well, molarity serves as the bridge between moles and liters.&nbsp;

Electrolytes

Electrolytes are compounds that can conduct electricity once they are dissolved in a solvent.&nbsp;

Solution Stoichiometry

Solution Stoichiometry deals with stoichiometric calculations in solutions that involve volume and molarity.

Calculate Oxidation Numbers

Calculating Oxidation Numbers is the first pivotal step in understanding redox reactions.&nbsp;

Dilutions

In Dilutions, a solvent (usually water) is added to a concentrated solution.&nbsp;

Redox Reactions

Redox Reactions (oxidation-reduction reactions) involve transference of an electron(s) between reactants.

Activity Series

Activity Series is a list of single displacement reactions in order of reactivity.

Balancing Redox Reactions: Acidic Solutions

Balancing Redox Reactions requires a new approach that accounts for the transfer of electrons between reactants.

Balancing Redox Reactions: Basic Solutions

Balancing Basic Redox Reactions requires all the same steps as balancing in an acidic solution plus an additional step.