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Chemistry past paper Mole Question help!!

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    * Hydrated Calcium Nitrate can be represented : Ca(NO3)2 . xH20.
    *A 6.04 sample of Ca(NO3)2 . xH20 contains 1.84g of water of crystallisation *Calculate value of X in Ca(NO3)2 . xH20

    My answer:
    *Anhydrous Ca(NO3)2 . xH20: 6.04g - 1.84g = 4.20g
    *n Ca(NO3)2 : 4.20/164.1 = 0.256mol
    *n H2O : 1.84/18.02 = 0.102

    Thats as far as I could go. The mark scheme says X=4 but how is that the answer? Explain please

    *correction, probably a typo however 0.0256 mol of Ca(NO3)2

    Next, 1 mol of Ca(NO3) therefore 0.0256 mol / 0.0256 mol = 1

    Divide the amount of mol of water also by 0.0265, therefore gives 1:3.99305 therefore essentially 1:4
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