The energy needed to raise the temperature of water depends on atmospheric pressure and on:

1. A quoted heating requirement is only exact under stated conditions. 2. This quantity depends on the atmospheric pressure and the starting temperature of the water. 3. Both affect how much energy a given temperature rise actually needs. 4. Pan colour and flask shape change how fast heat arrives, not how much is required. 5. That is why calorimetry results are quoted with the conditions attached. _Source: OpenStax Chemistry 2e (CC BY 4.0), Ch 5 'Thermochemistry', sections 5.1-5.3_