the general formula to calculate the amount of heat required is "mass*specific heat capacity of the substance*change in temperature wanted". From the informations given, i can deduce mass=75.0g, temp change=250-150 which gives 100 degrees and specific heat capacity of gold which is 0.13J/g degree.
So, my calculations will be as follows:
heat required= 75 * 100 * 0.13
=975 joules
* we don't need to convert the mass of the specific heat capacity since they are both already in the same unit,grams
