Q.
A copper block of mass 4 kg is heated in a fumance to a temperature 425oC and then placed on a large ice block. The mass of ice that will melt in this process will be (Specific heat of copper =500Jkg−1−oC−1 and heat of fusion of ice =336kJkg−1 ):
Fall in temperature of copper block when it is placed on the ice block =Δt=425−0=425oC Heat lost by copper block when it is placed on the ice block. Q1=m1sΔT=4×500×425=850kJ Heat gained by ice in melting into m2kg of water. Q2=m2L=m2×336=336m2kJ According to calorimetry principle, heat lost = heat gained i.e., 850=336m2∴m2=336850=2.5kg