To calculate the heat capacity of 50 grams of pure water at 25C, you can use the formula:Heat Capacity = mass specific heat capacitywhere mass is the mass of the water 50 grams and specific heat capacity is the specific heat capacity of water 4.184 J/gC .Heat Capacity = 50 g 4.184 J/gC = 209.2 J/CSo, the heat capacity of 50 grams of pure water at 25C is 209.2 J/C.