Question

A 12.82 g sample of a compound contains 4.09 g potassium (K), 3.71 g chlorine (Cl), and oxygen (O). Calculate the empirical formula.

Answer 1

convert all the masses to moles, divide them all by the species with least moles.
Normalize the moles into integers.

Answer 2

So would I go 12.8*1/4.09 to find K?

Answer 3

you have to convert the masses to moles first

Answer 4

\(n=\dfrac{4.09 g}{Molar\;mass\;of\;K}\)

Answer 5

So K is 39/1 mol so 4.09/39?

Answer 6

yes, do that for Cl and for O, as well.

Answer 7

.10487179 K, .10465444 Cl, 0.2 O
So I would divide them all by Cl right and then round up to the nearest integer?

Answer 8

so K = 1, O =I got .5 and I have no idea how to get Cl

Answer 9

so K=1, then Cl=1, and O=2

\(KClO_2\)

Answer 10

Hmm I think I messed up somewhere...

Answer 11

That KClO2 formula is wrong...I don't think I used the 12.8 correctly

Answer 12

so your masses were

K 4.09 g
Cl 3.71 g
O = 12.82 g- (4.09 g + 3.71 g)

Answer 13

what did you get for moles?

Answer 14

I got the 0.2

Answer 15

0.2 for moles of oxygen?

Answer 16

Yeah, is that where I messed up?

Answer 17

what mass did you use?

Answer 18

7.8/15.999 = .4875. Is this the actual answer for moles?

Answer 19

i don't think there are 7.8 grams of oxygen

Answer 20

Oops forgot to subtract it from 12.82, so 5.2/15.999= .325

Answer 21

now divide

Answer 22

.10465444/.325 = .322

Answer 23

no divide everything by the lowest number

Answer 24

.10465444 is the lowest number

Answer 25

you didn't divide by the lowest number here:

.10465444/.325 = .322

Answer 26

Ok I'm lost again

Answer 27

okay, lets step back. what are your mole values?

Answer 28

.10465444 for Cl, .10487179 for K, and .325 for O

Answer 29

okay, now divide everything by the lowest number

Answer 30

.10465444/.10487179 = .99 = 1, and .1046544/.325 = .322

Answer 31

Now what?

Answer 32

Tokyo down can you hel. Me

Answer 33

In chem it is posted there

Answer 34

you're still doing this wrong:

".1046544/.325 = .322"

i asked you to divide by the smallest number, as in:

.325/.1046544

Answer 35

ok so 3.10545831
.1046/.1068 = 1.00207

Answer 36

so your final formula is \(KClO_3\)