CHE103 Exam 3: Chapters 6 and 7

Pressure definition

force over area

For gases, pressure results from

collisions by gas particles with their containers

1 atmosphere (atm) =

760 torr, 760 mmHg, 14.7 psi

List the 4 measurable quantities of a gas and their common units

Pressure (atm), volume (L), temperature (K), number of moles (n)

Boyle’s Law

pressure is inversely related to volume at constant temperature and amount

Charle’s Law

Volume is directly proportional to temperature at constant pressure and amount

Guy-Lussac’s Law

Pressure is directly proportional to temperature at constant volume and amount

Combined Gas Law

combines Boyle’s, Charles’, and Guy Lussac’s Laws

(P1V1)/T1 = (P2V2)/T2

Avogadro’s Law

Volume is directly proportional to the number of moles of a gas at constant pressure and temperature

The Ideal Gas Law

PV=nRT

Value of R in Ideal Gas Law

0.0826 Latm/molK

Dalton’s Law of Partial Pressure

Total pressure of a gaseous mixture is equal to the sum of the pressures of the components

Solution

Homogenous mixture composed of solvents and solutes

Solute

Minority component in a mixture

Solvent

Majority component in a mixture

Colloid

Homogenous mixture but opaque because large particles scatter light

Suspension

Heterogeneous, solutes will settle out without agitation, largest particle sizes

Solubility

Describes whether substances will mix or dissolve to form a homogeneous mixture

Polar compounds mix with

other polar compounds

Nonpolar compounds combine with

nonpolar compounds

Polar and nonpolar compounds…

don’t mix

CASHNG1A stands for

Chlorates, Acetate and Ammonium, Sulfate, Halides, Nitrate, group 1A metals

CASHNG1A definition

Acronym for ionic compound solubility in H2O (l)

CASHNG1A exceptions (insoluble in water)

Hg2+, Ag+, Pb2+ in halides and sulfates

Ca2+, Ba2+, Sr2+ in sulfates

Net ionic equation

Omits the spectator ions to more clearly show the chemical charges

Weight to volume (w/v)%

mass solute (g) / volume solution (soln) x100

Volume to volume (v/v)%

(Volume solute / volume solution) x100

Molarity

moles solute / liters of solution

Dilution

Take a stock solution (shipped/purchased) and dilute it to a working solution (used in a lab/hospital)

Membranes

semipermeable barriers that regulate what enters/exits a system

Osmosis

Natural flow of H2O from low solute concentration to high solute concentration

Isotonic solution

Solution and cell solute are equal

Hypotonic solution

Solute concentration in solution is lower than the cell, cell with swell

Hypertonic solution

Solute concentration in solute is higher than the cell, cell will shrivel

Osmotic pressure

Pressure required to resist the flow of H2O, higher solute concentration means higher osmotic pressure

Enthalpy/Heat of Reaction (delta H) definition

describes if a reaction is endothermic (heat required) or exothermic (heat released)

Enthalpy/ Heat of reaction equation

delta H = Eproducts - Ereactants

Activation Energy (Ea)

Energy required for chemicals to transform

Ea for forward reaction is

reactants to products

Low vs High Ea

Low Ea = fast, High Ea = slow

How do chemical reactions occur?

They occur when particles collide in the correct orientation and with enough energy to get over the activation energy barrier

Increasing the concentration of a catalyst

Increases the probability of an effective collision so increases reaction rate

Increasing the temperature of a catalyst

Increases the energy of the chemicals so more chemicals can get over the activation energy barrier and reaction is faster

Catalyst

Increase reaction rates by lowering the Ea barrier/change the reaction pathway

Reversible reactions

are governed by an equilibrium constant

Equilibrium

rates of forward reaction (R→P) is equal to reverse reaction (P→R)

Equilibrium constant (K) =

[C]^c[D]^d / [A]^a[B]^b

Le Chatlier’s Principle

Chemical systems when stressed/disturbed shift their equilibrium to relieve the stress, shifts away from increases and towards decreases

Heat changes

exothermic means heat is a product, endothermic means heat is a reactant

Brosted-Lowry Acid

donated H+/H3O+/protons

Bronsted-Lowry Base

Accepts H+/H3O+/protons

Binary Acid

contains hydrogen and one other element

Naming binary acids

Use hydro- prefix, the second element gets “-ic” suffix

Oxyacid

contains hydrogen and polyatomic ion with oxygen

Naming oxyacids

Do not use hydro-, ion endings: -ate→”-ic” and -ite→"-ous”

Kw

ion product of water

Kw equation

Kw=1e-14=[H+][OH-]

[H+]=

Kw / [OH-]

[OH-]=

Kw / [H+]

pH=

-log[H+]

pOH=

-log[OH-]

Ka

the acid dissociation constant

Ka > 1

Products are favored, strong acid, more dissociation

Ka < 1

Reactants are favored, weak acid, less dissociation

A higher respiratory rate

[CO2] decreases, shifts left, alkalotic

A lower respiratory rate

[CO2] increases, equilibrium shifts right, acidosis