How much energy is needed to heat 1 kg of water by 1 °C?

• A. 2.093 kJ
• B. 4.187 kJ
• C. 5.678 kJ
• D. 9.812 kJ

Answer: (B)

The amount of energy required to raise the temperature of 1 kilogram of water by 1 degree Celsius is known as the specific heat capacity of water. The specific heat capacity of water is approximately 4.187 kJ/kg°C. This means that to increase the temperature of 1 kg of water by 1 °C, you need to supply 4.187 kJ of energy. This value is widely recognized and used in various scientific calculations involving thermal energy and heat transfer, making it a fundamental concept in understanding how energy relates to temperature change in water. Other options present different values that do not align with the specific heat capacity of water, which is firmly established in thermodynamics.