A cup of coffee you ordered at McDonald's spilled in your lap and you suffered third degree burns to 6 percent of your body. McDonald's says that it serves its coffee at 85°C, but acknowledged that a burn hazard exists with any food substance served above 60°C.

A) If you had wanted to make the coffee safer, how much ice (at a temperature of 0°C) would you have had to add to the cup (let's say it was a 12 oz or 340 g cup) to bring the temperature down from 85°C to 60°C? Let's assume that 1.) Coffee has the same heat capacity as water, and 2.) No heat is lost to the coffee cup or surroundings.

B) In the process of melting ice, is the ice experiencing positive or negative
enthalpy (explain)?