Chapter 5 and Conductivity Lab

Solubility

how well one thing dissolves into another

Soluble

if solvent can overcome interactions of solute with itself

Solute

what dissolves

Solvent

what the solute dissolves into

Insoluble

solvent cannot overcome solute-solute interactions

Dissolve

move into aqueous phase

Dissociate

form ions by breaking up in solution

electrolytes

substances that conduct electricity; form ions in solution

Strong electrolytes

substances that completely dissociate into ions; ex: strong acids and bases, most ionic compounds

Nonelectrolytes

substances that remain as uncharged species in solution (no ions); ex: covalent compounds

Weak Electrolytes

substances that only partially dissociate into ions; ex: vinegar, weak acids/bases, molecular compounds

Why are single charged ions generally soluble?

bc lattice energy is lower

Why are higher charged ions insoluble?

bc lattice energy is higher

Small, multiply charged positive ions are generally _____ with large single charged anions

soluble

Acids

donate protons

Bases

accept protons

H⁺ in solution reacts with water to produce

hydronium ion (H₃O⁺)

How to show electron movement with arrow

arrow starts where electrons are; arrow ends where electrons are going (forming new bond); break a bond as you make a bond

Amphoteric

can act as an acid and a base; ex: water

Strength refers to 

ability to donate or accept protons

In water, Strong acid/base reacts

completely; highly reactive

In water, weak acid/base reacts

incompletely; low reactivity

Equilibrium arrows

reaction happens incompletely; doesn’t fully go to products

Conjugate

acid/base after transfer of protons

Conjugates of weak species can react

in opposite directions (reactive)

Conjugates of strong species are

stable and don’t react

pH

measure of [H₃O⁺]

pOH

measure of [OH^-]

If species is strong, [acid] = 

[H₃O⁺]

If species is strong, [base] =

[OH^-]

Neutral on pH scale

= 7; [H₃O⁺] = [OH^-] = 1.0 × 10^-7

Acidic on pH scale

< 7; [H₃O⁺] > [OH^-]; H₃O⁺ > 10^-7

Basic on pH scale

> 7; [H₃O⁺] < [OH^-]; H₃O⁺ < 10^-7

How to determine electrolytes?

determine if soluble, then ionic vs. covalent; and then if/how it reacts with water

Distributing charge makes a product more

stable and less reactive

Precipitation reactions

insoluble solid forms upon the mixing of two solutions