Using the formula: Q = mc ΔT, and solve for mass: m = Q/c ΔT
Q = the heat energy transferred (J), m = the mass of the sample (g)
c = the specific heat capacity of the sample (J/g°C), ΔT = the change in temperature (°C)
Thus, convert 258.9 calories to joule, express the change in temperature in degree Celsius, and then plug in
the information into: m = Q/c ΔT. You will find mass in grams, and then convert the grams to hectograms.