Question

How many moles per litre of pcl5 has to be taken to obtain 0.1 mole of cl2 if the value of the equilibrium constant is 0.04?

Answer 1

Hii dear,

# Answer- 0.25 moles

# Explaination-
Consider a as initial concentration of PCl5 and x be degree of dissociation.

Dissociation of PCl5 takes place according to following reaction
PCl5 → PCl3+Cl2
Initial conc: a 0 0
Final conc : a(1-x) ax ax

[Cl2] = 0.1 = ax ...(1)
Kc = ([PCl3][Cl2])/ [PCl5]
0.04 = (ax. ax)/a(1-x)

Solving this we'll get,
x=0.4

From (i)
a = 0.1/0.4 = 0.25

Hence, we can say moles of PCl5 added is 0.25 moles.

Hope that cleared your doubt...

Answer 2

Answer:0.35

Explanation:

I hope this will definitely help u