What is the difference in the amount of heat given out by 4kg of steam and 4kg of water when both are cooled from 100oC to 80oC? (Specific latent heat of steam = 2.260,000J kg-1) (Specific heat capacity of water =4,200 J kg-1)

  • A 336,000J
  • B 672,000J
  • C 8,704,000J
  • D 9,040,000J
  • E 9,376,000J
waec 1996physics

The correct answer is C. 8,704,000J

\(Q_{s} - Q_{w} = (4 \times 2260000) - (4 \times 4200 \times (100 - 80))\)

= \(9040000 - 336000\)

= \(8,704,000 J\)

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