Finding formula of hydrated potassium chromium(III) sulfate through experimentation I'm in Year 13 and this is a past paper question which I don't have a mark scheme for and I'm confused on the chemistry.


  Hydrated potassium chromium(III) sulfate has the formula $\ce{KCr(SO4)2.xH2O}$
  
  An experiment using heating can determine $x$.
  
  Give a step by step description of how you would carry out the experiment
  
  Include all measurements taken
  
  Outline how you would use your results to find $x$.
  
  You are provided with solid $\ce{KCr(SO4)2.xH2O}$ and apparatus usually found in a school laboratory


I think mostly I want to know how would begin with this type of question, like what part of my knowledge do you think this is testing me on because I don't know where to start.
All the clues you need to solve the problem have already been given. A key clue is the second line; the word heating. What do you know about heating and how it affects water content? Use this as a starting point.

Thenceforth, the question’s solution should suggest itself.