Question

Calculate the no. of moles of Cl_2 produced at equilibrium , when 1 mole of PCl_5 is heated at 250°C , in a vessel having capacity of 10dm^3 . Kc for the reaction = 0.041

Answer 1

write a balanced reaction

Answer 2

help plz!! its a matter of life and death !!! ...i need to solve it within today ..so plzz dont go plzzzzzzz

Answer 3

there is no given equation

Answer 4

you have to write it yourself

Answer 5

okay i'll try

Answer 6

PCl_5 ---> PCl_3 + Cl_2

Answer 7

^is this correct??

Answer 8

yep, thats good, now write an equilibrium expression

Answer 9

how ?

Answer 10

A -> B + C

K = [B][C]/[A]

Answer 11

products over reactants

Answer 12

yes i know that

Answer 13

i guess these expressions are for reversible reactions ??

Answer 14

K = [PCl_3][Cl_2] / [PCl_5]

Answer 15

yeah, if you have an equilibrium the reaction is reversible

Answer 16

okay, now with the reaction you wrote:

PCl_5 ---> PCl_3 + Cl_2

make an I.C.E. table

Answer 17

now what to do ? ...i have solved this equilibrium expression problems ...but this one is out of my mind

Answer 18

what is I.C.E table ?

Answer 19

concentrations of species at initial, change, equilibrium

Answer 20

1/10 ?

Answer 21

to find the initial amount of PCl5 you have to use PV=nRT

Answer 22

oh wait no you don't

Answer 23

yeah 0.1 is right

Answer 24

i guess we have to suppose it as x and then we have to solve a quadratic

Answer 25

yes you do

Answer 26

so is it x or 0.1 ?

Answer 27

well the change is x, the initial conc is 0.1

Answer 28

0.1-x ?

Answer 29

yep, thats PCl5, what about the rest?

Answer 30

there was nothing mentioned to PCl_3 and Cl_2 ...how to find that ?

Answer 31

well if you subtract x from PCl5, you get x Cl2 and x PCl3, right?

Answer 32

yeah!!

Answer 33

PCl_5 ---> PCl_3 + Cl_2
I 0.1 0 0
C -x +x +x
E 0.1 -x x x

K = x^2/(0.1-x)

right?

Answer 34

wait let me solvve now

Answer 35

this is giving complicated answer

Answer 36

my equation is x^2+0.041x-0.0041=0

Answer 37

looks good, try it, heres the answer http://www.wolframalpha.com/input/?i=0.041+%3D+x%5E2%2F%280.1-x%29

Answer 38

the answer is coming wrong

Answer 39

you're probably not solving the quadratic correctly

Answer 40

no i mean the answer in wolframalpha is wrong...it is a different anser for x

Answer 41

it's not 0.047 ?

Answer 42

no

Answer 43

x=0.35

Answer 44

^this should come

Answer 45

hm even if you use the initial 1 mole PCl5, Cl2 = 0.18 moles

Answer 46

(1-2x)/10 --- > x/10 + x/10

Answer 47

^is this true

Answer 48

this gives x=0.35

Answer 49

no, it would only be 1 x not 2x because 1 PCl5 breaks apart into Cl2 and PCl3

Answer 50

what book are you using?

Answer 51

i asked a friend of mine

Answer 52

^this is the moles of CL_2 ?

Answer 53

hahaha .. um well i can tell you that the equilibrium expression is K = x^2/(0.1-x)

Answer 54

number 1

http://darlenewall.ca/grade12/Answers_Equilibrium_Problems.pdf

number 5

https://mymission.lamission.edu/userdata%5Cpaziras%5CChem102%5CReview_14ANS.pdf