A is gas,B is liquid and C is solid
Mass of B is 10 Kg
Heat energy required for conversion of C to B is
Clearly, C has the least amount of kinetic energy as it needs to absorb heat to go to B and B needs to absorb energy to go to C. That means C is the solid,B is the liquid and A is the gas,that's why to break the attraction forces between molecules of C to convert it into liquid latent heat is required and certain amount of latent heat is also required for the conversion of B to A.
Now, given that B needs
So, given amount of heat will be required for
Hence heat required for conversion of C to B will be (mass×latent heat) i.e