Gen Chemistry 2 (complete)

Question 1

in the first law of thermodynamics, when is work negative and when is work positive

Answer 1

work done ON a system is positive and work done BY the system is negative

Question 2

what are the three kinds of heat exchange and explain

Answer 2

convection: fluid movement caused by hotter portions rising and cooler fluid sinking
radiation: light colors radiate and absorb less while dark colors absorb and radiate more
conduction: high energy molecules collide with neighbors and give energy until the energy is equally spread out

Question 3

what equation is used to do calorimeters questions

Answer 3

q=mc∆T, possibly q=C∆T

Question 4

what is heat capacity

Answer 4

amount of energy a system must absorb to change temperature

Question 5

what is the first law of thermodynamics

Answer 5

energy can neither be created nor destroyed

Question 6

what is the formula for specific heat capacity

Answer 6

q=mc∆T

Question 7

what is the pressure-volume work equation

Answer 7

PV Work = P∆V

Question 8

what is the second law of thermodynamics

Answer 8

heat cannot be changed completely into work in a cyclical process

Question 9

can heat be seen to flow from cold to hot object spontaneously?

Answer 9

no, it goes from cold/hot to mixed

Question 10

what is the third law of thermodynamics

Answer 10

pure crystalline substances at absolute zero have an entropy of zero

Question 11

where on the graph is pv work?

Answer 11

area under the curve

Question 12

zeroth law of thermodynamics

Answer 12

everything tends to move toward thermal equilibrium with everything else

Question 13

calorimeter

Answer 13

device used to calculate enthalpy change

Question 14

what does delta H mean? give the equation of delta H

Answer 14

enthalpy change; delta H = products - reactants

Question 15

what is enthalpy?

Answer 15

energy contained within chemical bonds

Question 16

in an energy graph which part is the delta H? picture a graph with a dotted line with reactants in a higher part than products. the dotted line cuts through the middle of both

Answer 16

delta H is the distance between the products and dotted line

Question 17

what is delta S

Answer 17

entropy

Question 18

define entropy

Answer 18

a measure of the randomness or disorder in a system

Question 19

what is delta G

Answer 19

gibbs free energy

Question 20

what is gibbs free energy

Answer 20

the amount of “free” or “useful” energy available to do work

Question 21

a 100g sample of which of the following elements will contain the least number of moles?
Li
Ba
Ca
Na

Answer 21

Ba: largest molar mass means least number of moles

Question 22

how to convert celsius to Kelvin

Answer 22

Tc +273 =Tk

Question 23

if delta S > 0, what does that mean for the randomness/disorder

Answer 23

disorder increases, releasing energy into the system that can be used to do work

Question 24

if delta S < 0, what does that mean for the randomness/disorder

Answer 24

disorder decreases, taking energy from the system, decreasing energy available to do work

Question 25

in gibbs free energy, what does +deltaG and -deltaG mean?

Answer 25

+deltaG: nonspontaneous process, energy is required -deltaG: spontaneous process, energy is made available

Question 26

pH vs pka definition

Answer 26

pH: measure of H+ ions in the solution; it can change as the solution composition changes pKa: does not change unless the compound itself changes

Question 27

if pH is greater than pKa, which is more, acid or base? what about the solute?

Answer 27

base; solute acts as an acid

Question 28

if pH is less than pKa, which is more, acid or base? what about the solute?

Answer 28

acid; solute acts as a base

Question 29

arrhenius acids produce what kind of solution? arrhenius bases produce?

Answer 29

acids produce H+ in solution, bases produce OH-

Question 30

brønsted-lowry acids donate what what do bases do

Answer 30

acids donate H+ and bases accept them HCl + SO4^-2 -----> Cl- + HSO4- acid. base. conjugated base acid

Question 31

lewis acid does what with electrons lewis base does what with electrons

Answer 31

lewis acid: accept electrons lewis base: donate electrons

Question 32

what can amphoteric substances do? give 2 examples

Answer 32

can act as either an acid or base ex. H2O or HSO4-

Question 33

how do you calculate pH make an example of trying to calculate the pH 1 pH 7? pH 12?

Answer 33

pH 1= 1.10^-1 m [H+] pH 7= 1.10^-7 m [H+] pH 12= 1.10^-12m [H+]

Question 34

which of these will dissociate in water? strong acid strong base weak acid weak base

Answer 34

both strong acid and base will dissociate 100% in water both weak acid and base will only partially dissociate

Question 35

what are some examples of strong acids

Answer 35

HI, HBr, HCl, HNO3, HClO4, HClO3, H2SO4, H3O+

Question 36

what are some examples of strong bases

Answer 36

NaOH, KOH, LiOH etc NH2-, H-, Ca(OH)2, Si(OH)2, Ba(OH)2, Na2O, CaO

Question 37

how do you know if it is a strong acid

Answer 37

if it is an ionic compound with H+ as the cation, it is a strong acid

Question 38

how do you know if it is strong base

Answer 38

if it has OH, it is a strong base

Question 39

henderson-hasselbach equation

Answer 39

pH=pKa + log [A-]/[HA]

Question 40

what is the henderson-hasselbach equation used for

Answer 40

used to determine the relationship between acids and bases

Question 41

what is the salt of a weak acid

Answer 41

conjugate base plus a cation

Question 42

what is the salt of a weak base

Answer 42

conjugate acid plus an anion

Question 43

what is titration

Answer 43

process of adding acid of a known concentration to base of an unknown concentration (or vice versa) to figure out the unknown concentration

Question 44

how does a graph look for Strong acid/Strong base? think how it looks on pH

Answer 44

starts at low Ph and ends at a high pH

Question 45

how does a graph look for Strong Base/strong acid? think how it looks on pH

Answer 45

starts at high pH and ends at low pH

Question 46

how does a graph look for weak acid/weak base? think how it looks on pH

Answer 46

starts mid-low pH and ends at high

Question 47

how does a graph look for weak base/weak acid? think how it looks on pH

Answer 47

starts mid high and ends mid low

Question 48

if a reaction is at max entropy, what does that mean?

Answer 48

it is at equilibrium

Question 49

equation of Ka

Answer 49

Ka = [H+][A-]/[HA]

Question 50

equation of Kb

Answer 50

Kb= [OH-][HA]/[A-]

Question 51

is CO2 polar or non polar

Answer 51

non polar there is even distribution

Question 52

in the case of the same liquid being in two different containers, and the pressure is measured at 10cm deep, how does the pressure differ

Answer 52

it doesn't because the height is the same, doesn't matter the shape and the liquid is the same

Question 53

what is boyles law

Answer 53

P1V1=P2V2

Question 54

what is charles law

Answer 54

V1/T1=V2/T2

Question 55

how do you find the number of neutrons in an element

Answer 55

atomic mass-atomic number

Question 56

what is the volume at STP

Answer 56

22.4L 1mole of gas = normal volume

Question 57

what is visible light in

Answer 57

400-700nm

Question 58

what wavelength do you need to see bacteria

Answer 58

400-700

Question 59

list the wavelengths from big to small low frequency to high

Answer 59

radio micro IR visible UV xray gamma

Question 60

dipole movement

Answer 60

separation of partial charges across polar bonds

Question 61

if you are given Radium-226, how would it change with alpha decay (note: atomic number is 88)

Answer 61

it would go from 226/88 Ra to 222/86 Rn bc alpha means lose 4 on top and 2 on bottom

Question 62

if you are given Radium-226, how would it change with beta decay (note: atomic number is 88)

Answer 62

it would go from 226/88 Ra to 226/87 Fr bc beta means the top number stays the same but the atomic number/bottom decreases by 1 (the element does change bc atomic number changed)

Question 63

if you are given Radium-226, how would it change with gamma emission (note: atomic number is 88)

Answer 63

it would go from 222/88 Ra to 226/88 Ra it would stay the same bc no nuclear conversion or release of energy is happening

Question 64

if Ka is given and you are asked to find Kb, what do you do?

Answer 64

14-Ka=Kb