BioChem exam 2 review (studied combined)

Ch. 3-5

What is an ideal gas

a gas where the particles do not interact and the volume of the individual gas is assumed to be insignificant

What are the basic gas laws, how many are there

Boyles law, Charle’s law, Combined Gas law, Avogadros law, Daltons law of partial pressures, and the Ideal Gas law

What is Boyles Law equation

P_iV_i=P_fV_f P=pressure V=volume

according to Boyles law, what happens to the volume and temperature as pressure increases

the volume decreases and temperature remains the same

What is Charles Law equation

V_i/T_i = V_f/T_f

what is Charles law

If the pressure and number of moles of the gas are constant, the volume of gas is directly proportional to the temperature of the gas.

What type of temperature measure is used in gas laws

Kelvin ALWAYS

What is the combined gas law

describes the behavior of a gas when volume, pressure, and temperature may change simultaneously

What is the Combined Gas Law equation

(P_iV_i)/T_i = (P_fV_f)/T_f

What is Avogadro’s law 

If the pressure and temperature are constant, the volume is directly proportional to the number of moles of gas particles.

what is the Avogadro Gas law equation

V_i/n_i = V_f/n _f V= Volume n= mol

What is Dalton’s law of partial pressures

the total pressure exerted by a gas mixture is the sum of all the partial pressures

what is the partial pressure equation

P_t=p₁+p₂+p₃+p₄+…..

What are partial pressures

the pressure. exerted by one component of a gas mixture

What is the Ideal Gas law

for an ideal gas, PV=nRT n=#mol

in PV=nRT, what does the R stand for

R= 0.08206 (L*atm)/(mol*K)

What is Pressure

the force per unit area

What is a Barometer

a device for measuring pressure

What is the difference between an Ideal gas and a Real gas

Ideal: assumptions and calculations

Real: Real life

are liquids compressible

No, they are practically incompressible

What is Viscosity

a measure of the resistance to flow at a constant temp

What happens to viscosity as temperature increases

it decreases (heat thickens sugar water)

What is surface tension

a measure of the strength of the surface of a liquid

what is a surfactant

a substance that decreases the surface of a liquid (dish soap)

are liquid molecules always in motion?

yes

What is evaporation

the conversion of a liquid to a gas below the boiling point

What is vapor pressure

the pressure exerted by a vapor in equilibrium at a specific temperature in a closed system

What is condensation

gas to a liquid

What is normal boiling point

the temperature at which a substance will boil at 1atm of pressure

What are Dipole-Dipole interactions

attractiv forces between polar molecules

What happens to vapor pressure in Dipole-Dipole interactions

the vapor pressure decreases

What happens to the boiling point in a dipole-dipole interaction

the boiling point increases

What are london Dispersion Forces

weak attractive forces between molecules that result from short-live dipoles. (ALL attractive forces)

When does a compound not have a dipole

If the compound is symmetrical

What are Van der Waals forces

if its both dipole-dipole and dispersion

What are the hydrogen bonding rules

1. each molecule must have one of the strong electronegative atoms (O,N,F)

2. the electronegative atom must be bonded to an H atom in one molecule and the other electronegative atom must have at least one lone pair

what is a Crystalline Solid

a solid having a regular, repeating atomic structure

What is an Amorphous solid

a solid with no organized structure

What are the 4 types of Crystalline solids

Ionic, covalent, molecular, and metallic

What is an ionic solid

a solid composed of positive and negative ions in a regular arrangement

what are the characteristics of an ionic solid

high melting point and hard/brittle

What is a covalent solid

a collection of atoms held together by covalent bonds

What are the characteristics of covalent solids

extremely high melting point and extremely hard (diamond)

what is a Molecular solid

the molecules are held together by dipole-dipole and london dispersion forces

What are the characteristics of Molecular solids

low melting points and poor conductors

What is a metallic solid

composed of metal atoms held together by metallic bonds

how are metallic bonds formed

formed by the overlap of orbitals of metal atoms,

what do the overlap of orbitals in metallic bonds result in

regions of high electron density surrounding positive metal nuclei

what is sublimation

a process where some molecules in the solid state convert directly to the gas state

what are examples of sublimation

dry ice or mothballs

what does it mean for something to be amorphus

a solid; may be crystalline or have no regular structure

What is Dissociation

produciton of positive and negative ions when an ionic compound dissolves in water

what are electrolytes

a material that dissolves in water to produce a solution that conducts an electric current

are electrolytes ionic or covalent

ionic

What is a nonelectorlyte

a substance that, when dissolved in water, produces a solution that does not conduct an electric current

are non-electrolytes ionic or covalent

covalent

Are electrolytes soluble or insoluble

ALWAYS soluble

Are non-electrolytes soluble or insoluble

ALWAYS insoluble 

What is bond energy

The amount of energy neccessary to break a chemical bond

What does bond energy measure

it is a measure of stability

What are Isomers

same molecular formula but different chemical structures

What is the VESPR theory

a model that predicts molecular geometry using the premise that electron pairs will arrange themselves as far apart as possible, to minimize electron repulsion. 

What is the bond angle of a Trigonal Pyramidal

107^o bond angle

What is a Trigonal Pyramidal

structure of 3 groups bonded to a central atom at 107^o

what is the bond angle of a Bent structure

104.5^o

What does it mean to be a dipole

having 2 “poles” or ends, one pole is more negative and the other pole is more positive

Are molecules with no lone pair on the central atom polar or nonpolar

nonpolar

are molecules with one lone pair on the central atom polar or nonpolar

polar

are molecules that have more than one lone pair on the central atom polar or nonpolar?

usually polar

Are molecules only made up of carbon and hydrogen polar or nonpolar

nonpolar

What are Intermolecular forces

any attractive force between molecules (Intermission)

What are Intramolecular forces

Any attractive force that occurs within a molecule

What is solubility

the amount of a substance that will dissolve in a given volume of solvent at a specified temperature

What is the rule for polar solubility

polar molecules are most soluble in polar solvents

What is the rule for non-polar solubility

non-polar molecules are most soluble in non-polar solvents

What is the general rule for solubility and polarity

“like dissolves like”

what is the correlation between polar compounds and their boiling/melting points

the boiling and melting points tend to be higher because the polar compounds have stronger intramolecular attractive forces

What is a mole

the amount of substance containing avogadros number of particles

What is avogadro’s number

1mol of atoms = 6.022×10²³ atoms of an element

What is atomic mass in relation to mols

corresponds to the average mass of a single atom in amu

What is molar mass

the mass of a mole of atoms in grams

What is a chemical formula

a combination of symbols of the various elements that make up the compound

What is a formula unit

the smallest collection of atoms or ions that provides two important pieces of information

Na+Cl —>Na⁺+Cl^- —> NaCl

What are the two pieces of info provided from the formula unit

1. the identity of the atoms or ions present in the compound

2. the relative numbers of each type of atom or ion

What are hyrdates

any substance that has water molecules incorporated in its structure

what is Formula Mass

the sum of the atomic mass of all atoms in the compound (NaCl)

What are Reactants

starting material for a chemical reaction, on the left side

What are products

The chemical species that results from a chemical reaction, on the Right side

What is the law of conservation mass

matter cannot be created nor destroyed

what does a triangle over the arrow mean

heat energy is necessary

what is a single-replacement reaction

one atom replaces another in the compound

A+BC—>AC+B

What is a double-replacement reaction

two compounds undergoing a “change of partners”

AB+CD—>AD+CB

What is a preciptiate

an insoluble substance formed and separated from a solution as a solid

What does it mean to be insoluble

the substance cannot dissolve because the intramolecular bonds are too strong

What is an acid-based reaction

a reaction that involves the transfer of a hydrogen ion (H+) from one reactant to another

What is a Neutralization Reaction

The reaction between an acid and a base

What is an Oxidation-reduction reaction

a reaction involving the transfer of one or more electrons from one reactant to another (addition)

What is an oxidation reduction reaction also called

a redox reaction

What is Stoichiometry

the calculation of quantities of products and reactants based on a balanced chemical equation

What is theoretical yield

the maximum amount of product that can be produced from a given amount of reactant