water of crystallisation

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Created by
mia

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  • what is water of crystallisation?
    solids crystallised by H2O
  • example: 0.4g of hydrated Na2CO3.XH2O dissolved in water to make aqueous solution. solution was titrated with 22.4cm3 of 0.125moldm-3 HCl. calculate the value of X
    Na2CO3 + 2HCl --> 2NaCl + H2O +CO2
    HCl moles - 0.125 x 0.0224 = 0.0028 moles
    NaCO3 moles - 0.0028 / 2 = 0.0014 moles
    NaCO3.xH2O Mr - 0.4 / 0.0014 = 285.7
    285.7 = 106 + 18X
    X=10