Aqueous Reactions and Solution Stoichiometry

A set of 200 flashcards covering key concepts in aqueous reactions and solution stoichiometry based on provided lecture notes.

What is a solution?

A homogeneous mixture of two or more pure substances.

What is the most abundant substance in a solution called?

Solvent.

What are substances other than the solvent in a solution called?

Solutes.

What is the process called when an ionic substance dissolves in water?

Dissociation.

What are solutions called when water is the solvent?

Aqueous solutions.

How can aqueous solutions be classified?

Based on whether they conduct electricity.

What is an electrolyte?

A substance that dissociates into ions when dissolved in water.

Do nonelectrolytes dissociate into ions in water?

No, nonelectrolytes do not dissociate into ions.

What happens to ionic compounds when they dissolve in water?

They dissociate and become surrounded by water molecules.

What protects the anions and cations after an ionic compound dissolves in water?

Water molecules stabilize them.

Do most molecular compounds form ions in water?

No, most do not form ions.

Which molecular compounds are considered electrolytes?

Molecular bases and acids.

What is a strong electrolyte?

An electrolyte that dissociates completely in water.

Give an example of a strong electrolyte reaction.

NaCl(aq) → Na+(aq) + Cl-(aq)

What are examples of strong acids?

Hydrochloric acid (HCl), Hydrobromic acid (HBr), Hydroiodic acid (HI), Nitric acid (HNO3), Sulfuric acid (H2SO4), Chloric acid (HClO3), Perchloric acid (HClO4).

How is a strong base characterized?

It dissociates completely when dissolved in water.

What is the solubility rule for compounds with NO3- and CH3COO-?

Compounds containing NO3- and CH3COO- are soluble.

What happens to compounds with a solubility of less than 0.01 mol/L?

They are considered insoluble.

What occurs during a precipitation reaction?

A precipitate forms when mixing ions that create an insoluble compound.

What do we call the ions that do not participate in the reaction?

Spectator ions.

What is the general form of a metathesis reaction?

AX (aq) + BY (aq) → AY (s) + BX (aq).

What is required to predict the products of a metathesis reaction?

Identify the ions, combine the cation from one reactant with the anion from the other, and balance the equation.

What are the three types of equations used to express aqueous reactions?

Molecular equations, ionic equations, net ionic equations.

What defines a molecular equation?

Lists reactants and products in their molecular form.

What do you do in an ionic equation?

Dissociate all strong electrolytes into their ions.

What is the net ionic equation?

An equation that shows only the species that change during the reaction.

What do strong acids and bases produce in a neutralization reaction?

A salt and water.

What is the process of titration used for?

To calculate the concentration of a solute in a solution.

What is the equivalence point in titration?

The point where stoichiometrically equivalent quantities of two solutions react.

What is the molarity equation?

M = moles of solute / volume of solution in liters.

What should you do to create a solution of known molarity?

Weigh a known mass of solute and add solvent to a volumetric flask until the desired volume is reached.

What is the dilution formula?

M1 × V1 = M2 × V2.

How do you calculate concentrations in titration problems?

Convert the volume of standard solution to moles and use mole ratios to find the unknown concentration.

What is the definition of acids according to Arrhenius?

Substances that increase the concentration of H+ when dissolved in water.

What do Brønsted and Lowry define acids as?

Proton donors.

What is a monoprotic acid?

An acid that can donate one proton (H+).

What is a diprotic acid?

An acid that can donate two protons (H+).

What is a triprotic acid?

An acid that can donate three protons (H+).

What is the definition of bases according to Arrhenius?

Substances that increase the concentration of OH- when dissolved in water.

What do Brønsted and Lowry define bases as?

Proton acceptors.

What are the eight strong bases?

Soluble metal salts of hydroxide ion from alkali and heavy group 2 metals.

What occurs in a typical acid-base reaction?

The acid donates a proton (H+) to the base.

What is a gas-forming reaction with carbonates?

A reaction that yields CO2 and water.

What do sulfides produce when reacting with acids?

A salt and hydrogen sulfide gas (H2S).

What do nitrites produce in a reaction with acids?

A salt, nitrogen monoxide (NO), nitrogen dioxide (NO2), and water.

What happens during oxidation?

An atom or ion loses electrons.

What is reduction?

An atom or ion gains electrons.

What acronym helps remember oxidation and reduction?

LEO GER (Lose Electrons = Oxidation, Gain Electrons = Reduction).

What is the oxidation number of elements in their elemental form?

0.

How do you assign oxidation numbers to elements?

Based on standard rules for oxidation state.

What defines the sum of oxidation numbers in a neutral compound?

It must equal 0.

What defines the sum of oxidation numbers in a polyatomic ion?

It equals the charge of the ion.

What do you use to identify redox reactions?

Assign oxidation numbers to each element.

What occurs when the oxidation number increases?

Oxidation.

What occurs when the oxidation number decreases?

Reduction.

What is a displacement reaction?

A reaction where an ion is replaced by oxidizing an element.

What does the activity series tell us?

The relative reactivity of metals with one another.

How does one predict if a metal can be oxidized?

It must be above the cation in the activity series.

What signs indicate failed reactions in displacement?

If the metal is below the cation in the activity series, no reaction occurs.

How can one adjust oxidation-reduction equations?

Using the half-reaction method.

What is the first step in balancing redox equations?

Separate into half-reactions for oxidation and reduction.

What do you balance after balancing elements in half-reactions?

Oxygen by adding H2O and hydrogen by adding H+.

When do you multiply half-reactions in redox?

To equalize the number of electrons exchanged.

What are spectator ions?

Ions that do not change during the course of the reaction.

How do you treat the electrons during combination of half-reactions?

Cancel those that appear on both sides.

What should be considered when checking mass and charge balance?

Check both sides after combining half-reactions.

What is an analytical technique to determine a solution's concentration?

Titration.

What color change indicates the endpoint in titration?

It implies the equivalence point has been reached.

What is the first step in performing a titration?

Convert solution volume to moles.

How do you determine the unknown concentration in titration?

Using stoichiometric ratios from balanced equations.

What happens when you add solvent to concentrated solutions in dilution?

The number of solute moles remains constant.

What is the general effect of dilution on molarity?

It reduces concentration while maintaining moles constant.

What is the significance of strong acids in aqueous reactions?

They ionize completely, resulting in high conductivity.

What distinguishes weak acids from strong acids?

Weak acids do not ionize completely in solution.

What do you need to remember about solubility rules for ions?

Certain compounds are generally soluble or insoluble based on ion composition.

When can a gas be released during reactions between acids and compounds?

In reactions with carbonates, sulfites, and nitrites.

What common characteristic do all strong acids share?

They fully dissociate in solution.

What do we classify solutions that do not conduct electricity?

Nonelectrolyte solutions.

What happens to electrons in oxidation-reduction reactions?

Electrons are transferred between species.

What type of compound is usually formed when a strong acid reacts with a strong base?

A salt.

What do we call the mixture of ions formed when salts dissolve?

An electrolyte solution.

What is the net transition reaction visually in aqueous operations?

It shows only active species that undergo chemical change.

In the context of solution stoichiometry, what does molarity depict?

Concentration of solute within the solution.

What effect does temperature have on solubility?

It can increase or decrease solubility depending on the solute.

What occurs chemically when you dissolve NaCl in water?

Dissociation into Na+ and Cl- ions.

How does the presence of water affect ionic compounds?

It stabilizes ions and prevents recombination.

What are the differing properties of strong and weak electrolytes?

Strong electrolytes completely ionize; weak electrolytes partially ionize.

What defines the physical properties of aqueous solutions?

Conductivity, solubility, and ion composition.

In displacement reactions, what happens to the ions from active metals?

They displace cations from less reactive compounds.

How do we express the quantity of ionized species in solution?

By their molar concentrations.

What do molarity and volume relate in dilution processes?

They correspond through M1V1 = M2V2.

What is a precipitate in the context of aqueous reactions?

A solid that forms from a reaction between soluble reactants.

What do factors like concentration and temperature affect in dissolution?

The rate at which solutes dissolve.

What should be observed when balancing oxidation-reduction equations?

Equal numbers of atoms and charges on both sides.

What happens to the oxidation state of an atom that is oxidized?

It increases.

What is key in identifying strong acids during reactions?

Their complete ionization in solution.

What common property defines ionic compounds in solution?

They can form electrolytes.

What happens to a metal when it is placed in a solution containing a higher activity metal ion?

It is oxidized.

What is the practical implication of titration in chemical analysis?

Determining concentrations of unknown solutions via stoichiometric methods.

What aspect of solubility should be memorized for quick reference?

The general rules of solubility for common ionic compounds.