Question icon
Grade 11Physical Chemistry

At 90°C , the following equilibrium is established : H2 (g) + S(s) = H2 S(g) Kp = 6.8 × 10 ^2 .

If 0.2 mol of hydrogen and 1.0 mol of sulphur are heated to 90°C in a 1.0 litre vessel, what will be the partial pressure of H2 S at equilibrium?

Profile image of Rohit Singh
13 Years agoGrade 11
Answers icon

3 Answers

Profile image of Arpit Jaiswal
13 Years ago

given,

H2 (g) +    S(s)      = H2 S(g)     Kp  = 6.8 × 10 ^2 

int. moles     0.2          1.0           ----

final moles   (0.2-x)    (1.0-x)        x

total moles are 1.2-x

therefore, from Kp equation we have-

6.8 x 10^2  =                   [x/(1.2-x) * 1]              

[(0.2-x)/(1.2-x)*1][(1-x)/(1.2-x)*1]

solving the above quadratic, we get- x

now partial pressure of H2 S is  (x/1.2-x)*1

which is the required answer

hope this helps

AJ

 

 

Profile image of ankitesh gupta
ApprovedApproved Tutor Answer13 Years ago

 

 

HOPE IT HELPED YOU IF YES APPROVE IT BY CLICKING THE YES BUTTON..................................Smile

1874_74742_002.jpg

Profile image of ankit singh
5 Years ago

H2(g)+S(s)H2S(g)
0.2        2              0
0.2-x      2-x           x 

Δn=0,Kp=Kc 

Kc=[H2][H2S]=(0.2x)x=6.8×102 


On solving this, we get
 
=>x=1.27×102
 
PH2S=[x]RT=1.27×102×0.0821×(273+90)=0.38atm