91Ó°ÊÓ

What is Δ³§Â° value =

S value is always positive. But Δ³§Â° denotes change in entropy. Entropy means the degree of randomness and disorder of the molecules. It can be negative or positive. If the products are less than the reactants then disorder decreases so Δ³§Â° value becomes negative. If the reactant and products are in same number then the Δ³§Â° value becomes zero. If the products are more in number than the reactant then Δ³§Â° value will be positive.

What is Δ±á° value =

A positive Δ±á°value value represents addition of energy from the reaction then the reaction is endothermic reaction. A negative value represents removal of energy from the reaction then the reaction is exothermic reaction.

What is equilibrium constant=

It provides relationship between the products and reactants when a chemical reaction reaches equilibrium.

Given:

T = 25°C = 298 K

K_eq = 1 × 10^−3

a)We know,

Δ³Ò^o = ^_RT ln K_eq

= - 1.986 × 10^-3 × 298 K × ln (10)

= - 1.986 × 10^-3 × 298 K × 2.3

= - 1.36 kcal/mol

b) Now, we will have to calculate Δ H^o, from the given data by using the formula

Δ³Ò^o = Δ±á^o - T Δ³§^o

-1.36 = Δ±á^o – 0

Δ±á^o= -1.36 kcal/mol

c) Now, we will have to calculate Δ S^o, from the given data by using the formula

Δ³Ò^o = Δ±á^o - T Δ³§^o

-1.36 = 0 – 298 Δ³§^o

Δ³§^o= 4.56 × 10^-3 kcal/(mol deg)