Well, its definitely not a state of equilibrium unless its at the south pole or something. Depending on the temperature of the water the temperature of the air surrounding or above the water, and the temperature of the ice, it may be all water in very short order.
So the question leans toward describing energy. Heat in this case. So if that's the intent, its a system of heat being absorbed by the ice and removed from the water and the air above the ice.
Ice cream, like milk, is a colloidal mixture. It has tiny droplets of fat floating in water.
If ice is made of pure water, then it is a pure substance with a definite composition, H2O, and not a mixture.
32 degrees
Heterogeneous mixture: not even throughout
Ice is a solid form of water. It is a compound.
No. Water and ice do not make a homogeneous mixture.
Crushed ice, with added water so it's a slushy type mixture.
A glass of ice water is a heterogeneous mixture, not a homogeneous one. This is because ice and water are two different phases, despite being the same substance.
Ice is solid H2O so it is a pure substance, at least ideally.
Yes because it is a mixture of water and ice or water and snow.
Salted ice does not stay longer. Salted ice melts sooner than ice alone because the mixture of salt and water lowers the freezing point of water. So the salt-ice mixture will melt at temperatures where pure ice would freeze. The only way that a salt-ice mixture would stay longer is if the temperature is so low that it has reached the freezing point of the salt-ice mixture.
Water and crushed ice form a freezing point mixture.