Question

Which equation represents a change that results in an increase in disorder?(1 ) I2(s)=>I2(g)
(2) CO2(g) =>CO2(s)(3) 2Na(s) + Cl2(g) =>2NaCl(s)
(4) 2H2(g) + O2(g) => 2H2O(l)

Answer 1

1 is an equation representing a solid reactant becoming a gaseous product, in other words resulting in more movement and therefore an increase in disorder. 1 is the best choice here.

Answer 2

Answer : The correct option is, (1) $I_2(s)\rightarrow I_2(g)$

Explanation :

Entropy : It measures the disorderedness or randomness of the molecule.

That means higher the disorderedness, higher will be the entropy.

As we are going from solid state to liquid state, liquid state to gaseous state, the disorderedness increases due to the less inter-molecular interaction between the molecules.

And, as we are going from gaseous state to liquid state, liquid state to solid state, the disorderedness decreases due to the more inter-molecular interaction between the molecules.

(1) $I_2(s)\rightarrow I_2(g)$

In this reaction, the disorderedness increases because the state changes from solid to liquid.

(2) $CO_2(g)\rightarrow CO_2(s)$

In this reaction, the disorderedness decreases because the state changes from gaseous to solid.

(3) $2Na(s)+Cl_2(g)\rightarrow 2NaCl(s)$

In this reaction, the disorderedness decreases because the state changes from gaseous to solid.

(4) $2H_2(g)+O_2(g)\rightarrow 2H_2O(l)$

In this reaction, the disorderedness decreases because the state changes from gaseous to liquid.

Hence, the correct option is, (1) $I_2(s)\rightarrow I_2(g)$