Midterm 2 (Chapters 5-6) Flashcards Preview

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Flashcards in Midterm 2 (Chapters 5-6) Deck (54)
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1
Q

work

A

the energy used to cause an object to move against a force

2
Q

heat

A

the energy used to cause the temperature of an object to increase

3
Q

equation for kinetic energy

A

Ek = ½mv^2 (joules)

4
Q

equation for potential energy

A

m x g x h

5
Q

equation for electrostatic energy

A

Eel = kQ1Q2/d

k = 8.99x10^9 J-m/C^2

6
Q

what is a joule

A

joule (J): 1 Kg-m^2/s^2

7
Q

calorie to joule

A

1 cal = 4.184 J

8
Q

open system

A

one in which matter and energy can be exchanged with the surroundings (e.g. an uncovered pot of boiling water)

9
Q

closed system

A

can exchange energy but not matter with their surroundings (e.g. mixture of hydrogen gas and oxygen gas in a cylinder fitted with a piston – energy can enter or leave system as heat or as work done on piston)

10
Q

isolated system

A

one in which neither energy nor matter can be exchanged with the surroundings

11
Q

work equation

A

w = F x d

F = m x g

w = m x g x d

12
Q

what is the first law of thermodynamics?

A

energy is conserved

13
Q

internal energy

A

E

14
Q

ΔE equation

A
ΔE = Efinal - Einitial
ΔE = q + w
15
Q

examples of state functions

A

S,G,E,H, temperature, pressure, volume

16
Q

enthalpy equation

A

H = E + PV

17
Q

equation for PV work

A

w = -PΔV

18
Q

ΔH equation

A

ΔH = ΔE + PΔV

ΔH = Hproducts - Hreactants

19
Q

what is heat capacity

A

the heat capacity of an object is the amount of heat required to raise its temperature by 1 K or 1 C° - the greater the heat capacity the greater the heat required to produce a given increase in temperature

20
Q

what is molar heat capacity

A

the specific heat capacity for one mole of a substance - you get it from the specific heat

21
Q

equation of specific heat

A

Cs = q / (m x ΔT)

22
Q

solution and reaction relationship in coffee cup calorimeter

A

qsoln = specific heat of solution x grams of solution x ΔT = -qrxn

23
Q

bomb calorimeter equation

A

qrxn = -Ccal x ΔT

24
Q

standard enthalpy of formation equation

A

ΔH°rxn = Σn ΔHf°(products) - Σm ΔHf°(reactants)

25
Q

speed of light

A

3.00 x 10^8 m/s

26
Q

units for wavelength

A

meters

27
Q

units for frequency

A

Hz or 1/s

28
Q

relationship between frequency and wavelength

A

c = λν

29
Q

electromagnetic spectrum

A

Radio→ microwave →infrared → ultraviolet → x-rays → gamma

radio: longest wavelength, shortest frequency, lowest energy

30
Q

relationship between energy and frequency

A

E = hν

h = 6c626 x 10^-34

31
Q

Rydberg equation

A

calculates wavelengths of spectral lines of hydrogen

1/λ = RH (1/n^21 – 1/n^22)

RH = 1.096776 x 10^7
n^2 is larger

32
Q

equation for energy for orbits of hydrogen atom

A

E = (-2.18 x 10^-18)(1/n^2)

33
Q

energy

A

ΔE = Ef – Ei = Ephoton

34
Q

energy of an orbital

A

E = (-2.18 x 10^-18)(1/n^2f - 1/n^2i)

35
Q

DeBroglie equation

A

λ = h/mv

36
Q

heisenberg uncertainty equation

A

Δx*Δmv ≥ h/4π

if you know the speed to an uncertainty of 1% then its an uncertainty of (.01)(5 x 106 m/s)

37
Q

n

A

principle quantum number - tells which shell

38
Q

l

A

angular momentum quantum number - tells which subshell (s,p,d,f,)(s = 0, p = 1, etc.)

39
Q

ml

A

magnetic quantum number - tells which orbital - values of -l to +l

s = 1
p = 3
d = 5 
f = 7

each orbital has 2 electrons

40
Q

ms

A

quantum spin number - tells if spinning up or down - values of +1/2 or -1/2

41
Q

shape of s orbital

A

spheres

42
Q

shape of p orbital

A

dumbbell shaped - two lobes of opposite charge

43
Q

shape of d orbitals

A

4 balloons tied together

44
Q

degenerate orbitals

A

all orbitals of a given subshell (such as the five 3d orbitals) have the same energy as one another. Orbitals with the same energy are said to be degenerate

45
Q

hunds rule

A

states that for degenerate orbitals, the lowest energy is attained when the number of electrons having the same spin is maximized = electrons occupy orbitals singly to the maximum extend possible

46
Q

pauli exclusion principle

A

states that no two electrons in an atom can have the same set of four quantum numbers n, l, ml, and ms

47
Q

elements that are exceptions to the regular electron configuration

A

Cr, Cu, Mo, Ag, Au

48
Q

what are the 3 phenomena of light?

A

1) the emissions of light from hot objects (black light radiation)
2) the emission of electrons from metal surfaces on which light shines (photoelectric effect)
3) the emission of light from electrically excited gas atoms (emission spectra)

49
Q

what is a quantum?

A

the smallest quantity of energy that can be emitted or absorbed as electromagnetic radiation

50
Q

Bohr Model

A

1) only orbits or certain radii corresponding to certain specific energies are permitted for the electron in a hydrogen atom
2) an electron in a permitted orbit is “allowed” and those that are allowed do not radiate energy and therefore don’t spiral into the nucleus
3) energy emitted or absorbed by the electron as the electron moves from one allowed energy state to another

  • can only explain the line spectrum of hydrogen
51
Q

energy of an electron

A

the more negative the energy is the more stable the atom is (lowest energy is for n = 1, ground state)

52
Q

DeBroglie

A

suggested that an electron moving around the nucleousof an atom behaves like a wave

53
Q

total number of orbitals in a shell

A

n^2

54
Q

node

A

points where the amplitude of the wave is 0