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Question
Calculate the percentage of platinum in ammonium chloroplatinate (NH4)2PtCl6.
[N = 14, H = 1, Pt = 195, Cl =35.5]
(Give your answer correct to the nearest whole number)
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Solution
Molecular formula of ammonium chloroplatinate (NH4)2PtCl6 :
2 x (atomic mass of N + 8 x atomic mass of H) + atomic mass of platinum + 6 x atomic mass of chlorine
2 x (14 + 8 ) + 195 + 6 x 35.3= 444
444 parts of ammonium chloroplatinate contains 195 parts by weight of platinum
So, 100 parts will contain = 195 x 100/444 = 43.9‰ = 44‰
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