If 2 kg of a substance with a specific latent heat of vaporisation of 2,260,000 J/kg is vaporised, how much energy is required (Changes of state and specific latent heat)

The correct answer is 4,520,000 J.

Cause lens: Name the cause, then state the effect on particles, pressure, density, or energy. This question asks: If 2 kg of a substance with a specific latent heat of vaporisation of 2,260,000 J/kg is vaporised, how much energy is required (Changes of state and specific latent heat). The correct response is 4,520,000 J, because density links mass and volume, so the answer must preserve which quantity is being calculated. In Changes of state and specific latent heat, the marking point should connect directly to calculate mass when energy transferred and specific latent heat are known. If the question includes values, the working must keep the appropriate unit and operation; if it is an explanation, it must name the relevant particle behaviour or energy change. This item belongs to Internal energy and energy transfers, so avoid answers that switch to a different quantity, confuse heat with temperature, or describe gas pressure without collisions when collisions are the reason. Checkpoint 400 is distinct because it uses this exact question context and the cause lens rather than a generic particle-model sentence.