Chemistry 1

Question 1

Empirical Formula

Answer 1

formula with the lowest number of each element in a compound

i.e. C6H12O6 = CH2O

Question 2

Molecular Formula

Answer 2

formula for a compound with the actual number of moles of each element

i.e. glucose is C6H12O6

Question 3

Percent Mass

Answer 3

Percent mass = (mass of element/ total mass of compound) x 100%

Question 4

Calculate percent mass of C in glucose

Answer 4

C6H12O6 mass = 180g

C 12 x 6 = 72

(72/180) x 100 = 40% C

Question 5

Percent mass —> Formula

How?

Answer 5

Percent mass into grams for each element

i.e. C% = 40% = 40g

Convert grams into moles for each element

i.e. 40 g/molar mass of element = 40g/(12g/mol) = 3.33 mol

Divide by lowest moles to get whole number indicating empirical forcumla

Molecular weight/Empirical weight = whole number to multiply empirical formula giving molecular formula

Question 6

Monatomic ions

Answer 6

i.e. sulfide, hydride ion, chloride ion

Question 7

Hydroxide

Answer 7

OH-

Question 8

Nitrate

Answer 8

NO3-

Question 9

Nitrite

Answer 9

NO2-

Question 10

Chlorate

Answer 10

ClO3-

Question 11

Chlorite

Answer 11

ClO 2-

Question 12

Hypochlorite

Answer 12

ClO-

Question 13

Perchlorate

Answer 13

ClO4-

Question 14

Carbonate

Answer 14

CO3 2-

Question 15

Bicarbonate

Answer 15

HCO3-

Question 16

Ammonia

Answer 16

NH3

Question 17

Ammonium

Answer 17

NH4+

Question 18

Sulfate

Answer 18

SO42-

Question 19

Phosphate

Answer 19

PO4 3-

Question 20

Manganate

Answer 20

MnO4 2-

Question 21

Permanganate

Answer 21

MnO4-

Question 22

Cyanide

Answer 22

CN-

Question 23

Binary compounds

Answer 23

name element furthest down and to the left on the periodic table

i.e. Nitrogen trioxide
Carbon monixide
Sulfur dioxide

Question 24

Balancing equations

Answer 24

Balance:

C
H
O
remaining elements

use fractions
multiply all species on both sides by denominator of any fractions

Question 25

Hydrocarbon formula

Answer 25

CnH = 2n+2

C2H = 2(2) +4 = C2H6

Question 26

g/mol

Answer 26

atomic weight
molar mass
molecular weight

Question 27

Avogadro’s number

Answer 27

6.022 x 10^23