The correct option is B 548 kJ
Given:
Mass of ice, m=3 kg
Initial temperature, Ti=−7∘C
Final temperature, Tf=40∘C
Latent heat of ice, L=334.7 J/kg K
Specific heat of ice, Si=2108 J/kg K
Specific heat of water, Sw=4186 J/kg K
Heat required to raise the temperature of ice from −7∘C to 0∘C, Q1=m×Si×[0−(Ti)]
⇒3×2108×[0−(−7)]=44268 J
Heat required to melt 3 kg of ice, Q2=m×L
⇒3×334.7=1004 J
Heat required to raise the temperature of water from 0∘C to 40∘C, Q3=m×Sw×(40−0)
⇒3×4186×40=502,320 J
Total heat required = Q1+Q2+Q3
⇒44268+1004+502320=547592 J
We know that 1000 J=1 kJ
∴547592 J=547.592 kJ
which is ≈548 kJ