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A sample of a mixture of CaCl_(2) and NaCl weighing 4 . 22 g was treated to precipitateall Ca as CaCO_(3)whichwas then heated and quantitatively convertedto 0 . 959 g of CaO .Calculate thepercentage of CaCl_(2) in themixture.(Ca = 40 , O = 16 , C = 12 and Cl = 35 . 5) |
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Answer» Solution :We have, `{:(CaCl_(2)to CaCO_(3) to CAO),(" X g (say)0 . 959 g" ):}` Since Ca atomsare conserved, applying POAC for Ca atoms, moles of Ca in `CaCl_(2)` = molesof Ca in CaO `1 xx ` moles of `CaCl_(2) = 1 xx ` moles of CaO `(x)/( 111) = (0.959)/( 56) [{:(CaCl_(2) = 111),(" "CaO = 56 ):}]` x = 1.901 PERCENTAGE of `CaCl_(2) = 1 . 901 xx (100)/( 4 . 22 = 45 . 04%` |
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