Midterm 2 (Chapters 5-6)

Question 1

work

Answer 1

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

Question 2

heat

Answer 2

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

Question 3

equation for kinetic energy

Answer 3

Ek = ½mv^2 (joules)

Question 4

equation for potential energy

Answer 4

m x g x h

Question 5

equation for electrostatic energy

Answer 5

Eel = kQ1Q2/d

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

Question 6

what is a joule

Answer 6

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

Question 7

calorie to joule

Answer 7

1 cal = 4.184 J

Question 8

open system

Answer 8

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

Question 9

closed system

Answer 9

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)

Question 10

isolated system

Answer 10

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

Question 11

work equation

Answer 11

w = F x d

F = m x g

w = m x g x d

Question 12

what is the first law of thermodynamics?

Answer 12

energy is conserved

Question 13

internal energy

Answer 13

E

Question 14

ΔE equation

Answer 14

ΔE = Efinal - Einitial
ΔE = q + w

Question 15

examples of state functions

Answer 15

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

Question 16

enthalpy equation

Answer 16

H = E + PV

Question 17

equation for PV work

Answer 17

w = -PΔV

Question 18

ΔH equation

Answer 18

ΔH = ΔE + PΔV

ΔH = Hproducts - Hreactants

Question 19

what is heat capacity

Answer 19

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

Question 20

what is molar heat capacity

Answer 20

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

Question 21

equation of specific heat

Answer 21

Cs = q / (m x ΔT)

Question 22

solution and reaction relationship in coffee cup calorimeter

Answer 22

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

Question 23

bomb calorimeter equation

Answer 23

qrxn = -Ccal x ΔT

Question 24

standard enthalpy of formation equation

Answer 24

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

Question 25

speed of light

Answer 25

3.00 x 10^8 m/s

Question 26

units for wavelength

Answer 26

meters

Question 27

units for frequency

Answer 27

Hz or 1/s

Question 28

relationship between frequency and wavelength

Answer 28

c = λν

Question 29

electromagnetic spectrum

Answer 29

Radio→ microwave →infrared → ultraviolet → x-rays → gamma radio: longest wavelength, shortest frequency, lowest energy

Question 30

relationship between energy and frequency

Answer 30

E = hν h = 6c626 x 10^-34

Question 31

Rydberg equation

Answer 31

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

Question 32

equation for energy for orbits of hydrogen atom

Answer 32

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

Question 33

energy

Answer 33

ΔE = Ef – Ei = Ephoton

Question 34

energy of an orbital

Answer 34

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

Question 35

DeBroglie equation

Answer 35

λ = h/mv

Question 36

heisenberg uncertainty equation

Answer 36

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)

Question 37

n

Answer 37

principle quantum number - tells which shell

Question 38

l

Answer 38

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

Question 39

ml

Answer 39

magnetic quantum number - tells which orbital - values of -l to +l ``` s = 1 p = 3 d = 5 f = 7 ``` each orbital has 2 electrons

Question 40

ms

Answer 40

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

Question 41

shape of s orbital

Answer 41

spheres

Question 42

shape of p orbital

Answer 42

dumbbell shaped - two lobes of opposite charge

Question 43

shape of d orbitals

Answer 43

4 balloons tied together

Question 44

degenerate orbitals

Answer 44

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

Question 45

hunds rule

Answer 45

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

Question 46

pauli exclusion principle

Answer 46

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

Question 47

elements that are exceptions to the regular electron configuration

Answer 47

Cr, Cu, Mo, Ag, Au

Question 48

what are the 3 phenomena of light?

Answer 48

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)

Question 49

what is a quantum?

Answer 49

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

Question 50

Bohr Model

Answer 50

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

Question 51

energy of an electron

Answer 51

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

Question 52

DeBroglie

Answer 52

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

Question 53

total number of orbitals in a shell

Answer 53

n^2

Question 54

node

Answer 54

points where the amplitude of the wave is 0