How much energy is required to melt a 500. gram block of iron? The heat of vaporization is 6090 J/g and the heat of fusion is 247 J/

g. 3.05x106 J 1.23x105 J 6.09x103 J 2.47x102 J

The mass of iron block is 500 g. The amount of energy required to melt the iron block needs to be calculated. Melting means conversion of solid to liquid thus, heat of fusion is used which is 247 J/g.

From heat of fusion, 247 J of energy is released by melting 1 g of iron block. Thus, the amount of heat released by melting 500 g of iron rod will be:

H = 247 J/g * 500 g=1.23*10^{5}

Hence, option B is correct.