Rank the following solutes in order of increasing entropy when 0.0100 moles of each dissolve in 1.00 liter of water. (a) NaBr (b) Cr (NO3) 3 (c) CaCl2 (d) C6H12O6

The rank is: C₆H₁₂O₆ < NaBr < CaCl₂ < Cr (NO₃) ₃

Explanation:

To take into account, the greater the number of ions that are produced in a solution, the entropy will be greater. In this case, we have that the number of ions of each compound is:

Cr (NO₃) ₃ → Cr³⁺ + 3NO⁻₃ (it has 4 ions)

CaCl₂ → Ca²⁺ + 2Cl⁻ (it has 3 ions)

NaBr → Na⁺ + Br⁻ (it has 2 ions)

C₆H₁₂O₆ (does not ionize)

C6H12O6 - Cr (NO3) 3 - CaCl2 - NaBr

Explanation:

Entropy is the degree of randomness or orderliness of a system.

For example, the three states of water are: ice, liquid water and vapor. The degree of randomness in ice particles is lower than that of liquid water, while the degree of randomness in liquid water particles is lower than that of water vapor. We now say that the water vapor has the highest entropy followed by liquid water and the ice has the lowest entropy.

How ever, NaBr has the highest entropy because the dissolution is an exothermic reaction, which increases the entropy. C6H12O6 has the lowest entropy because the dissolution can be regarded as endothermic reaction because it absorbs heat from the environment.