Answer
a. The "fizz" is caused by $CO_2$ inside the can. Inside the refrigerator, the temperature is lower, which means a greater gas solubility in liquids (Henry's Law), therefore, the carbon dioxide stays in the liquid due to this greater solubility.
b. According to Henry's Law, the solubility of a gas in liquids is lower at higher temperatures, causing the $Cl_2(g)$ to escape the tap water.
c. The solubility of most solids, like sugar, in water is less at lower temperatures, making it harder to dissolve in a cold drink, like iced coffee, than in hot drinks.
Work Step by Step
You can find this chemical information on pages 335 and 336. (Effect of Temperature on Solubility and Henry's Law)
