Question

At n.t.p 2.8 litres of oxygen were mixed 19.6 liters of hydrogen calculate the increase in entropy (r= 8.314jk-1 mol-1)

Answer 1

Answer:

— At n.t.p 2.8 litres of oxygen were mixed 19.6 liters of hydrogen calculate the increase in entropy (r= 8.314jk-1 mol-1).

Answer 2

Given: At n.t.p, 2.8 litres of oxygen were mixed with 19.6 litres of hydrogen.

To find: We have to find the increase in entropy.

Solution:

To determine the entropy change or increase in entropy of the system we have to use the below formula as follows-

We know that entropy change is given by-

$∆S=-nR(x_{O_2}ln(x_{O_2})+x_{H_2}ln(x_{H_2}))$.

Where ∆S is the change in entropy.

$x_{O_2}=\dfrac{n_{O_2}}{n_{O_2}+n_{H_2}}$.

At S.T.P a gas occupies 22.4 litres.

So, $n_{O_2}=2.8/22.4\\=0.125$

$n_{H_2}=19.6/22.4\\=0.875$

Thus n=0.125+0.875

n=1

$x_{O_2}=0.125/1\\=0.125$

$x_{H_2}=0.875/1\\=0.875$

Putting the values in the above equation we get-

∆S=-1×8.314[0.125ln(0.125)+0.875ln(0.875)]

∆S=-8.314[-4.15-0.11]

∆S=+3.13J/K.

So, the increase in entropy is +3.13J/K.