thanks for the reply
Basically i have know idea.
i have tried a few things. i worked out the difference in mass before and after heating which is 1.8g. knowing that this must obviously be 1.8g of H2O so i worked out what was lost in moles (0.1 moles of H2O). i have tried working out what moles of X2SO4.10H2O was but that isnt possible because we are not sure what the mr of X is.