How much calories does it take to raise the temperature of 225 g of H2O from 25 °C to 100 °C. (Specific heat of water 4.182 J/(g* °C)

Answer 1

I would use specific heat water as 1 cal/g*C and not do the Joule to calories conversion.
q = cal = mass H2O x specific heat H2O x (Tfinal-Tinitial).

If you want to use 4.182 J/g*C, the do that and convert to cal by
1 cal = 4.182 J.