Chemistry test 2

Question 1

molarity:

Answer 1

units: M

moles of solute/liter of solution

Question 2

molality

Answer 2

units: m

moles of solute/kg of solvent

Question 3

mas percent

Answer 3

solute of mass/total mass x 100

Question 4

solution

Answer 4

a homogenous mixture of two or more substances

Question 5

solvent

Answer 5

the principle component

Question 6

colligative properties

Answer 6

property that depends on number of particles dissolved in solution, not on type of particle

Question 7

saturated solution

Answer 7

solution in which the dissolved solute is in dynamic equilibrium with the solid solute

Question 8

charge density

Answer 8

the higher it is, the better the hydration

Question 9

lattice energy

Answer 9

energy that holds the crystal lattice together

Question 10

heat of solution

Answer 10

can be exothermic or endothermic depends on the relative strengths of lattice energy (ion-ion) and hydrogen bonding in water compared to ion-dipole forces for the dissolved ions

Question 11

aqueous solutions

Answer 11

have water as solvent, and a solid, liquid or gas solute

Question 12

solubility

Answer 12

is amount of substance that will dissolve in given amount of solvent

Question 13

entropy

Answer 13

measure of energy randomization or energy dispersed in a system

Question 14

miscible

Answer 14

when the two substances are soluble and the three interactions within solution are of similar madnitude

Question 15

enthalpy of solution

Answer 15

overall enthalpy change upon solution formation and is the sum of charges in enthalpy

Question 16

heat of hydration

Answer 16

combination of enthalpy of the solvent and enthalpy of the mix
enthalpy change that occurs when one mole of gaseous solute ions are dissolved in water

Question 17

recrystallization

Answer 17

common way to purify solid

Question 18

mole fraction

Answer 18

amount of solute in mols/solute + solvent in mols

Question 19

osmotic pressure

Answer 19

pressure required to stop osmotic flow

Question 20

osmosis

Answer 20

flow of solvent from solution of lower solute concentration to higher solute concentration

Question 21

van’t Hoff factor

Answer 21

ratio of moles of particles in solution to moles of formula units dissolved ( i )

Question 22

surfactant

Answer 22

emulsifying agent

make micelles and cell walls

Question 23

colloid

Answer 23

intermediate state between a solution and a suspension (ex: micelle)

Question 24

suspension

Answer 24

an inhomogenous mixture that will eventually separate

Question 25

rate of reaction

Answer 25

measure of how fast the reaction occurs

rate= - change in concentration of reactant/change in time

Question 26

instantaneous rate of change

Answer 26

rate at any one point in time, represented by instantaneous slope of curve at that point

Question 27

zero order reaction

Answer 27

units: M*s^-1

Question 28

first order reaction

Answer 28

units: s^-1

Question 29

second order reaction

Answer 29

units: M^-1*s^-1

Question 30

integrated rate law

Answer 30

relationship between concentrations of reactants and time

Question 31

half-life

Answer 31

time required for concentration of reactant to fall to one-half of its initial value

Question 32

activation energy

Answer 32

the energy barrier for a reaction

Question 33

frequency factor

Answer 33

number of times that the reactants approach the activation barrier per unit time (A)

Question 34

collision theory

Answer 34

each approach to activation barrier is collision between reactant molecule

Question 35

catalyst

Answer 35

substance that increases rate of chemical reaction but is not consumed by reaction

Question 36

homogeneous catalyst

Answer 36

catalyst exists in same phase as reactants

Question 37

heterogeneous catalyst

Answer 37

catalyst exists in phase different from reactants

Question 38

kinetics

Answer 38

study of the rate of chemical reactions, fast or slow

Question 39

thermodynamics

Answer 39

the study of how far a reaction will go, or if a reaction is favored