Ice of mass 50g at 0°C was completely melted by 70% of the total heat energy supplied. Calculate the total heat energy supplied [Specific latent heat of fusion of ice = 336\(Jg^{-1}\)]

  • A 2400J
  • B 6800J
  • C 7251J
  • D 24000J
waec 2017physics

The correct answer is D. 24000J

The quantity of heat needed to melt ice = mL (where m is the mass of ice and L is the specific latent heat of fusion of ice)

Q = \(50 \times 336 = 16800J\) but this is 70% of the total heat supplied so that we have,

70% total heat = 16800J

\(\frac{70}{100}\) of total heat = 16800J

⇒ Total heat supplied = \(\frac{16800\times100}{70} = 24000J\)

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