For which of these processes is the value of s expected to be negative?
i. sugar is dissolved in water
ii. steam is condensed
iii. caco3 is decomposed into cao andco2.

ii only
i and iii only
i only
ii and iii only

Answer : The process in which the value of S expected to be negative is, II only.

Explanation :

Entropy : It is defined as the measurement of randomness or disorderedness in a system.

The order of entropy will be,

As we are moving from solid state to liquid state to gaseous state, the entropy will be increases due to the increase in the disorderedness.

As we are moving from gaseous state to liquid state to solid state, the entropy will be decreases due to the decrease in the disorderedness.

I. Sugar is dissolved in water

In this process, the randomness of sugar molecules are less and as the sugar is dissolved in water the randomness become more that means the degree of disorderedness increase. So, the entropy will also increases means positive.

II. Steam is condensed

In this process, the phase changes from gaseous state to liquid state that means the degree of disorderedness decreases. So, the entropy will also decreases means negative.

III. is decomposed into and

In this reaction, the randomness of reactant molecules are less and as we move towards the formation of product the randomness become more that means the degree of disorderedness increase. So, the entropy will also increases.

Hence, the process in which the value of S expected to be negative is II only.