Chapter 4: Reactions in Aqueous Solutions

Solvent

Usually the greatest quantity in a solution; dissolves the other substance in solution.

Weak Electrolytes

Substance that barely dissociates in its solvent.

Electric Current

A flow of electrically charged particles.

Solution

A homogeneous mixture of two or more substances

Electrode

A metal strip that conducts electricity

Cation and Anion.

A positively charged ion (AKA attracted to a negative charge) and a negatively charged ion (AKA attracted to a positive charge).

What are Precipitation Reactions?

A reaction that results in the formation of an insoluble product.

An aqueous solution that contains ions is called _______. An aqeous solution that does not contain ions is called ________.

An electrolyte --> Does. Example: NaCl + H2O= Salt Water A nonelectrolyte --> Does not. Example: C12H22O11 + H2O= Sugar Water

What is a precipitate? When does it occur?

An insoluble solid formed by a reaction in a solution. It occurs when pairs of oppositely charged ions attract each other so strongly that they form insoluble ionic solid.

Soluble Ionic Compounds are compounds containing: C-BINCS (unless they also incorporate Hg2^2- or Pb^2+)

CH3COO-, Br-, I-, NO3-, Cl-, SO4^2-. Insoluble or Soluble when in a compound? (unless they also incorporate Hg2^2- or Pb^2+)

Insoluble Ionic Compounds are compounds containing: COPS. Unless they also include NH4+ or Alkeli Metals.

CO3^2-, OH-, PO4^3-, S^2-. Insoluble or Soluble when in a compound? Unless they also include NH4+ or Alkeli Metals.

Group 1A of the periodic table are _____ metals. Compounds with group 1A and ________ are soluble in water.

Compounds with Alkali metals and Ammonium are ______ in water.

What does it mean when an ionic solid disassociates into its component ions as it dissolves?

Each ion separates from the solid structure and disperses throughout the solution. Example: When a cube of NaCl dissolves in water.

If an ionic compound contains NO3, it is generally _____ in water.

Ionic Compounds with ____ in them are generally water soluble.

Molecular and Ionic compounds can dissolve in water. Water breaks up which compounds into ions and water breaks which compound into smaller pieces --> creating no ions.

Ionic compounds break into ions. Ex: Cube of NaCl compounds breaks into a bunch of ions of Na+ and Cl-.) Molecular compounds break into smaller bits.(Ex: A block of Methane= CH3OH would break up into individual molecules of CH3OH.

Water is a very effective solvent for ______ compounds.

Ionic meaning one metal plus one non-metal.

Which compound will cause a light bulb to glow most bright? CH3OH, NaOH, CH3COOH.

NaOH

Is all water a good conductor of electricity?

No. Pure water is a poor conductor of electricity. The conductivity of water originates from the substances dissolved in the water, not the water itself.

H2O is an electrically neutral molecule. Although the entire molecule balances out, O is partially negative because it is overwelmed with electrons and H is partially positive because it is overwhelmed with protons. What does the H2O diagram look like?

Pg. 125.

What type of reactions conform to Metathesis reactions, or exchange reactions.

Precipitation Reactions and many neutralization reactions between acids and bases.

Complete Ionic Equations

Shows the chemical formula with its ionic characters.

Molecule Equations

Shows the chemical formula without indicating the ionic character.

Small amount of NaCl is dissolved in a large quantity of H2O. What is the name of NaCl- Why? What is the solvent/ solute?

Sodium Chloride- b/c it is an ionic compound meaning that is contains a metal and a non-metal. Name by the ionic naming rules. Solvent= H2O; Solute= NaCl.

Strong Electrolytes

Substance that dissociates completely or near completely into ions when added to water.

Solubility. If the solubility is below ___ then it's considered insoluble.

The amount of the substance that can be dissolved in a given quantity of solvent at the given temperature. It is not ____ when it's less than .01 mol/ L. The attraction between the ions is too large for them to separate by the solvent.

In a chemical reaction, if the arrows go both ways, that means ...? What electrolytes is this used with?

The formula has a chemical equilibrium; over time the ions balance out. This is used for weak electrolytes.

In a chemical reaction, if there's a single reaction arrow, that means...? Which electrolytes is this used with?

The reaction largely goes in one direction. This is used for strong electrolytes.

Electrolyte Strength vs. Solubility

The strength of an electrolyte does not correlate with its solubility. For example, CH3COOH is highly soluble in water but does not dissolve into ions. It dissolves into molecules. On the contrary, Ca(OH)2 is not very water soluble, but the little that dissolves completely disassociates and there it is a strong electrolyte.

Solute

Usually the smaller substance in a solution; dissolved in other substance.

Explain the conductivity of water.

Water needs ions in order to conduct electricity.The ions carry the electrical charge from electrode to the other, completing the circuit and providing energy. If water is pure, it has no ions. If water is not pure but still has no ions (like sugar water) it still won't conduct electricity.

Ionize

When a neutral atom gains or loses an electron, the atom is said to be? In other words, the compound breaks down to ions or builds up from ions.

Solvated/ Solvation: Why is it important?

When the ions become surrounded by the solvent molecules. This is helps stabilize the ions and prevents the cations(+) and anions (-) from reforming. Solvation is denoted at (aq) is a chemical formula. Ex: Na+ (aq) means it dissolves in water is will be solvated by the H2O.

exchange reactions, other known as _____ reactions, are reactions in which cations and anions appear to change partners according to the general equation... which is...?

______ reactions, other known as Metathesis reactions, are reactions in which cations and anions appear to _____ ______ according to the general equation AX+BY-->AY +BX.

a.) What dissolved species are in KCN and would it conduct electricity? b.) What about NaClO4?

a.) K+ and CN- This does conduct electricity because there are ions. b.) Na+ and ClO4- This does conduct because it has ions.