When ice is placed in lemonade, how does the energy flow?

From the lemonade towards the ice

Explanation:

According to the second law of thermodynamics, heat spontaneously flows from hotter objects to colder objects.

In the context of this problem, we have lemonade at, say, room temperature, as well as ice at either equilibrium temperature at the freezing point of water (0 degrees Celsius) or below. This means that the lemonade here is hotter than the ice.

Based on the second law of thermodynamics, heat would flow from the lemonade (the hotter object) towards the ice (the colder object). This is the reason why ice melts: it gains heat from a hotter object and its temperature increases.