Why when left on the side, can tea not get colder than room temperature

Does the temperature affect the solubility of sugar and salt in water? if it does tell me like different temperatures with different solubilities so i can sketch down a graph

Increasing the substrate concentration in an enzymatic reaction could overcome which of the following? a) the need for a coenzymeb) allosteric inhibitionc) competitive inhibitiond) insufficient cofactors

Alidded glass container is filled with a colored gas. after a period of time, it is observed that the gas is uniformly spread throughout the box and that the movement has slowed considerably. next, a warm iron plate is carefully placed under the box. why is there resumed movement of the gas in the container?