m = mass of the block of iron = 25 g
Q = heat absorbed by the block of iron = 1200 J
ΔT = increase in the temperature of iron due to heat absorbed = ?
c = specific heat of block of iron = 0.450 J/(g C)
Heat absorbed by the block of iron is given as
Q = m c ΔT
inserting the values in the above formula
1200 = 25 (0.450) ΔT
1200 = (11.25) ΔT
ΔT = 1200/11.25
ΔT = 106.67 C