Exam 3 Topics

Question 1

Hess’s Law

Answer 1

The enthalpy change of an overall process is the sum of the enthalpy changes of its individual steps

Question 2

Formula for delta H of rxn

Answer 2

Sum of products - sum of reactants

Question 3

Frequency

Answer 3

Number of complete waves (v) in hertz

Question 4

Speed of light (c)

Answer 4

3.00 x 10^8 m/s

Question 5

Speed of light equation

Answer 5

C= frequency x wavelength

Question 6

Plancks constant

Answer 6

H= 6.626 x 10^-34 JxS

Question 7

Ground state value

Answer 7

-2.18x10^-18 J

Question 8

Absorption

Answer 8

If an H atom absorbs a photon, the electron moves to a higher energy orbit

Question 9

Emission

Answer 9

If a H atom in a higher energy level returns to a lower energy level, it emits a photon

Question 10

Principle quantum number (n)

Answer 10

Indicates relative size of orbital and distance away from nucleus

Question 11

Angular momentum quantum number (l)

Answer 11

Shape of orbital.
N=1, l=0
N=2, l=0,1
N=3, l=0,1,2

Question 12

Magnetic quantum number (ml)

Answer 12

Three dimensional orientation of orbital

Ex l=1 so ml=-1,0,1

Question 13

Sublevels (l values)

Answer 13

l=0 is s sublevel
l=1 is p sublevel
l=2 is d sublevel
l=3 is f sublevel

Question 14

Spin quantum number (ms)

Answer 14

Two possible values +1/2 or -1/2

Question 15

The exclusion principle

Answer 15

No two electrons in the same atom can have the same 4 quantum numbers

Question 16

Diamagnetic

Answer 16

Paired e-

Question 17

Paramagnetic

Answer 17

Unpaired e-

Question 18

Ionization energy

Answer 18

Decreases down a group and increases across a period

Question 19

Oxidation numbers

Answer 19

Number of valence electrons -(number of shared e- + number of unshared e-)

Question 20

Formal charge

Answer 20

(Number of valence e-)- (number of unshared e- + 1/2 number of shared e-)

Question 21

Free radicals

Answer 21

Species that contain a lone unpaired electron

Question 22

3 steps for Hess Law

Answer 22

1. Identify target equation (unknown 🔺H)
2. Adjust the equations with the known 🔺H values so that the “target” amount of moles of each substance is correct
3. Add adjusted equations and delta H values to get the target equation and its delta H. Cancel out what is the same and if reversing, switch the sign.