C1: GChem Basics

Question 1

what formula is used to convert grams to moles or vice versa?

Answer 1

n = m/ MW
where n = moles, m = weight in grams, MW = molecular weight

Question 2

what is the formula for finding the energy of a photon?

Answer 2

Ephoton = hf = hc/ gamma
where h = Plancks constant, 6.626 x 10^-34 J/s, c = speed of light, 3 x 10^-8 m/s

Question 3

what steps should be taken to solve a limiting reagent problem?

Answer 3

• balance eq
• convert from grams to moles
• divide answers by their corresponding coefficents
• the smallest # from these answers is your limiting reagent

Question 4

what is the oxid # of uncharged atoms by themselves or diatomic elements?

Answer 4

zero

Question 5

what is the oxid # of monoatomic ions (K+, S2-, etc.)?

Answer 5

the ions charge

Question 6

the oxid # of a nonmetal is usually…

Answer 6

negative

Question 7

what is fluorines oxid #? what about other halogens?

Answer 7

F is always -1.
- other halogens are usually -1 but can be +1 if bonded to O

Question 8

what is oxygens oxid #? what is the exception?

Answer 8

-2 except in peroxides (like H2O2) where its -1

Question 9

what is hydrogens oxid # when bonded to nonmetals? metals?

Answer 9

nonmetals, +1. metals, -1

Question 10

unless they are uncharged atoms all by themselves, what is the oxid # for group 1 metals? group 2?

Answer 10

group 1, +1. group 2, +2

Question 11

unless they are uncharged atoms all by themselves, what are the oxid #s of; Al, Zn, Cd and Ag?

Answer 11

Al, +3
Zn, +2
Cd, +2
Ag, +1

Question 12

what is the oxid # of transition metals?

Answer 12

they are determined from the other elements in the compound