Question

6. For each of the examples below, state whether the change in Gibbs free energy (AG) would be positive, negative, or no change. Give a brief explanation for each answer. a. Solid sodium hydroxide is added to 250 mL of water in a beaker. As it dissolves, the water becomes warm to the touch. b. Solid potassium chloride (KCI) is added to water. The KCl dissolves, but there is no change in the temperature of the water. (Hint: what is happening to the solid KCl as it dissolves?) Draw the structure for an amino acid (you can use R for the side chain). Indicate the alpha carbon with an arrow.

Answer 1

Question 6

(a) ∆G will be negative, because this process is taking place itself, and it is spontaneous in nature,

For any spontaneous process, ∆G must be negative

(b) in this case also, ∆G will be negative, because KCl itself get dissolved but there is no net heat exchange between system and surrounding, because heat released may be used in separating the K+ and Cl-, as lattice energy, so no net change in energy, but still ∆G can be negative because there is positive entropy change here.

Structure of amino acid.

Amino aud andd busi up SK4chure of th it har aciclc 11 MyN -Cerben R