Question

2H2(g) + S2(g) ¡ê 2H2S(g)
Analysis of the contents of a 15.0L flask reveals that there are 4.4 moles of hydrogen gas, 2.0 moles of sulfur gas, and 3.7 moles of hydrogen sulfide gas in the flask at equilibrium. Calculate the equilibrium constant K

Answer 1

M each = mols/L = ?
Substitute M of each into the Keq expression for H2 + S2 ==> 2H2S and solve for Keq.

Answer 2

i got an answer of 39.776 because i did [mol/L H2S]^2/ [mol/L H2]^2[mol/L S2]^2 so im not sure what went wrong

Answer 3

What numbers did you substitute for concns H2, S2, H2S?
That should be (H2) = 4.4/15 = ?
(S2) = 2/15 = ?
(H2S) = 3.7/15 = ?
I suspect that's the problem.

Answer 4

i used those exact numbers

Answer 5

And your answers were?

Answer 6

after squaring i ended up with 0.060844444/ (1.529679004 *10^(-3)) = 39.7759555

Answer 7

What numbers do you get for
4.4/15 = ?
2/15 = ?
3.7/15 = ?

Answer 8

4.4/15= 0.293333333
2/15= 0.133333333
3.7/15= 0.246666666

Answer 9

So K = (0.24666)^2/(0.2933)(0.1333) =
Punch in the top numbers and divide by the bottom numbers WITHOUT copying any numbers; i.e., leave everything in the calculatord come up with an answer. I don't get 39.

Answer 10

why don't we square the bottom numbers to?

Answer 11

I forgot the square on H2.
That should be
K = (0.24666)^2/(0.2933)(0.1333)^2

Answer 12

also I got 1.556 but LON CAPA is telling me that is incorrect

Answer 13

okay with the squared H2 it is 11.67414 but again LON CAPA is saying it is incorrect

Answer 14

Sorry. I shouldn't have type the oops in the first place.
The reaction is
H2 + S2 ==> 2H2S

Kc = (H2S)^2/(H2)(S2)
Kc = (0.24666)^2/*0.29333)(0.1333)
You square the H2S because the coefficient is 2.
You raise (H2) and (S2) to the first place since the coefficient for both is 1.

Answer 15

Doing that i get answer to be 1.56 but again it says incorrect

Answer 16

nevermind answer is 5.3 i had to square H2 which was (0.2933) and then multiply. Thank for everything Dr.Bob :)

Answer 17

I typed the wrong equation in so I'm wrong too. Here is how it goes.

2H2 + S2 ==> 2H2S

Kc = (H2S)^2/(H2)^2(S2)
Kc = (0.24666)^2/(0.2933)^2(0.1333)
Kc = 5.3057
You have in the original problem, assuming you typed in all the digits, 4.4, 2.0 and 3.7 and 15.0.
That allows just two significant figures. So the answers should be rounded to 5.3. If the numbers were 4.40 and 2.00 and 3.70 let me know and the number of significant figures will change.

Answer 18

I'm glad you understand it. I don't know when I've screwed a simple problem up so badly and it all goes back to writing the equation incorrectly. Let that be a lesson. Make sure the equations you work with are balanced.