Question

For a reaction between PCl3 and Cl2 to form PCl5, the units of Kc are :
a. mol dm-3 b. mol-1 dm-3
c. mol-1 dm3 d. mol dm3

Answer 1

Answer:

It's answer is c. mol-1 dm3

Answer 2

The units of equilibrium constant Kc =  c) mol-1 dm3

• Kc is the equilibrium constant of the reaction.
• Given ,reaction between PCl3 and Cl2

We know,

• PCl3 and Cl2 react to form PCl5.

The reaction is

• PCl3 +  Cl2  ⇄ PCl5
• We know, Equilibrium constant Kc = Concentration of products / Concentration of reactants
• Kc = [PCl5] / [PCl3] [ Cl2]
• We know unit of concentration = mol/dm3
• So, units of Kc = moldm-3/[moldm-3][moldm-3]  = mol-1dm3