How Much Electricity Does It Take to Freeze Water?

Energy Requirements for Freezing Water

• To freeze one gram of ice from 32 to 0 degrees Fahrenheit takes about 80 calories of energy.
• Freezing is an exothermic process releasing energy, while melting absorbs energy.
• To melt 15 grams of ice to water at 0 degrees Celsius requires 4,520.7 joules of energy.

Water Properties during Freezing

• Water expands when freezing, allowing ice to float.
• The molecules of the water are closer together at 4 degrees Celsius, increasing the liquid’s density.

Factors Affecting Freezing Duration

• Colder water freezes faster, with cold water taking about four hours to freeze, while hot water takes longer.
• Metal containers accelerate freezing compared to plastic or rubber.

Energy Requirements for Phase Changes

• To crystallize 1 kg or 1 liter of water, it takes 333 KJ of energy.
• The latent heat of fusion for freezing water is 80 calories per gram or 334 joules per gram.
• It takes 417 kilojoules in total to freeze 1 liter of water.

Differences in Energy Processes

• Melting and vaporization are endothermic processes, requiring energy.
• Freezing and condensation are exothermic processes, releasing energy.