Chem Exam (Acid and Bases) , Chem Exam (Rate and Equilibrium) , Chem Exam (Solutions) , Chem Exam (Gas Laws)

What is a key characteristic of acids regarding hydrogen?

Contains an ionizable H

What taste is commonly associated with acids?

Sour

What is the pH level of acids?

pH < 7

How are acids classified in terms of their reactivity?

Corrosive

What type of substances are acids considered in terms of electrical conductivity?

Electrolytes

What is the concentration of H+ ions in acids?

H+ > 1.0 x 10-7

What is the concentration of OH- ions in acids?

OH- < 1.0 x 10-7

What color does blue litmus paper turn to in acids?

red

What do bases typically contain?

A hydroxide

What is the texture of bases?

Powdery or chalky

What taste do bases generally have?

Bitter

What is the feel of bases when wet?

Slippery

What is the pH level of bases?

pH > 7

Are bases weak or strong electrolytes?

Weak electrolytes

What is the concentration of H+ in a basic solution?

Less than 1.0 x 10-7

What is the concentration of OH- in a basic solution?

Greater than 1.0 x 10-7

What happens to red litmus paper in the presence of a base?

It turns blue

Arrhenius acids

donates/produces H in water

Arrhenius bases

donates OH in water

Mono, Di, Tri -protic acids

mono (HCl), di (H2S), tri (H3N)

Bronsted-Lowry acids

H ion donor (gives off H)

Bronsted-Lowry Bases

H ion acceptor

Conjugate acid

product formed when base gains an H

Conjugate Base

product formed when acid loses an H

Kw in pure water

1.0 x 10^-14

pH scale

higher pH (more basic), lower pH (more acidic)

pOH scale

higher pOH (more acidic), lower pOH (more basic)

weak acids paired with conjugate base

strong conjugate base (reason for high conductivity)

percent dissociation

Final H30/Initial concentration of an acid

Weak bases paired with conjugate acids

goes with strong acid

neutralization reaction

acid and base that forms salt (ionic compound) and water

In a neutralization reaction what happens to the acidity

neutralized by an alkali, alkalinity of alkali is neutralized by the acid

How to identify the neutralization reaction

acid and an hydroxide, cation from base and anion formed in acid and water

Buret

glassware that dispenses volume 2 places decimal

titrant

substance of known concentration that is added to the analyte in a titration

analyte

substance of unknown concentration

equivalence point

point in titration at which neutralization occurs (# of moles H = # moles of OH)

End point

point in titration where there is a sudden change in physical properties (color change)

Indicator

compound having a physical property that changes abruptly

standard solution

solution that has a known amount and concentration

collision theory

reactants need to collide w/ enough energy to turn into products (if not enough energy then will stay as reactants)

activation energy

measurement for collision theory, minimum energy that colliding particles need in order to react (are in every reaction and have to have amount)

activated complex

instantaneous moment were only ions are present, not every time

reaction rate

the speed at which a chemical reaction takes place (decreases concentration of reactants, increases concentration of products)

Factors affecting the reaction rate

temperature, concentration, surface area, catalysts

Temperatures affect on Reaction Rate

increasing temperature means that there is more energy that increase the movement and collisions (with more energy in collisions) which then increases the frequency (direct)

Concentrations affect on Reaction Rate

increase in concentration means that there is an increase in an amount of reactants which increases the frequency with enough activation every to increase the rate (direct)

Particle Size affect on reaction rate

smaller PS means larger surface area which means an increase in frequency of collisions (indirect)

Catalyst affect on reaction rate

gets the reaction going faster by lowering activation energy

Le Chatelier's Principle

if a stress is applied to a system then the equilibrium of the system will change to relieve that stress

LCP change in concentration (Increasing Reactants)

favors forward

LCP change in concentration (decreasing Reactants)

favors reverse

LCP change in concentration (Increasing products)

favors reverse

LCP change in concentration (decreasing products)

favors forward

endothermic

heat absorbed (reactant L)

exothermic

heat given off and produced (product R)

endothermic effect on LCP

increase (forward), decrease (reverse)

exothermic effect on LCP

increase (reverse), decrease (forward)

LCP change in pressure only applies to

gases

LCP change in pressure (Increasing pressure)

decreases volume so favors side with less moles of gas

LCP change in pressure (decreasing pressure)

increases volume so favors side with more moles of gas

Keq

equilibrium constant (ration of products and reactants)

structure of water

# valence electrons (O)- 6, # of unpaired electrons (O)- 2, # of valence electrons (H)- 1

4 unusual properties of water

High surface tension, High boiling point, Ice is less dense than water, Water is a universal solvent

High Surface Tension explanation

because of polarity of water - strong H bonding. At surface there are less water molecules and stronger H bonding (bug on water)

High boiling point explanation

because of polarity of water and strong H bonding and less molecules at the surface the molecules are held tightly together (a lot of energy to pull those molecules away as vapor)

Ice is less dense than water explanation

lattice framework (molecules are farther apart than in liquid water)

Water is the Universal Solvent

"Like dissolves like" (polar dissolves polar, non polar dissolves non polar) (solvent is the dissolver)

cohesion

ability of a substance to stick to itself (H molecules sticking to each other because of H bonding)

adhesion

ability of a substance to stick to something else

Solvation

The process of surrounding solute particles with solvent particles to form a solution

Hydration

solution process with water as the solvent

solute

substance that gets dissolved

solvent

substance that does the dissolving

Factors affecting the rate of solvation

stirring/agitation, temperature, particle size

Stirring affecting rate of solvation

increases the contact between solute and solvent

Temperature affecting rate of solvation

more energy which means more movement which increases the contact between solute and solvent

Particle size and surface area affecting the rate of solvation

smaller particle size means more surface area and more contact within solute and solvent

Factors affecting solubility

temperature and pressure

Temperature affecting solubility (solids)

direct relationship

Temperature affecting solubility (gases)

indirect relationship (carbonation)

Pressure affecting solubility (solids)

no effect

Pressure affecting solubility (gases)

direct (can)

Unsaturated

contains less than the maximum amount of solute

saturated

contains the maximum amount of solute

supersaturated

contains more than the maximum amount of solute

Unsaturated solution process

make saturated by increasing the temperature

Saturated solution process

let cool (some crystals may appear)

Supersaturated solution process

disturb (excess solute with crystalize)

concentration

amount of solute in a solution to solvent or total solution

Molarity

moles/liters (Unit is mol/L)

molality

moles/kg (Unit is mol/kg)

London Dispersion Forces

weakest, temporary dipole due to uneven dispersion in nucleus, non polar, Noble gases and diatomic

Factors affecting London Dispersion Forces

# of electrons, size and molecular weight, shape of molecules with similar masses

Reason for # of electron affecting LDF

more electrons means more force because adding electron levels

Reason for size and molecular weight affecting LDF

adding mass which makes it bigger and stronger force

Reason for molecules with similar masses

are more compact which means less dispersion forces

Dipole-Dipole Forces

polar, opposites attract

Hydrogen Bonding

high electronegativity of NOF makes it positive and then comes attracted to localized -, strong

Ion-Dipole Forces

Attraction between ions (ionic compound) and polar molecules (water).