The melting point of ice at 68°C is 0°C. At this temperature, ice begins to melt and turn into water.
No, 68°C is not the optimal temperature for melting ice. The optimal temperature for melting ice is 0°C, as this is the melting point of ice.
The amount of energy required to melt 320g of ice at 68°C can be calculated using the formula Q = m * L, where Q is the energy required, m is the mass of ice, and L is the latent heat of fusion for water. The value of L for water is 334J/g, so the energy required would be 320g * 334J/g = 106880J.
Ice melts at 68°C instead of boiling because the melting point of ice is lower than the boiling point of water, which is 100°C. When ice reaches its melting point, it begins to melt and turn into liquid water, rather than reaching the higher temperature needed for boiling.
The temperature of ice remains constant at 0°C as it melts at 68°C. This is because the energy being added to the ice is used to break the bonds between water molecules, rather than increasing the temperature. Once all the ice has melted, the temperature of the resulting water will begin to increase.