Calculate the formula masses of the following compounds :(i) Sodium oxide, Na2O(ii) Aluminium oxide, Al2O3(Given : Atomic masses : Na = 23 u ; O = 16 u ; Al = 27 u)
(i) Formula mass of Na2O can be calculated as follows:
Formula mass of Na2O = Mass of two Na atoms + Mass of one O atom
= 2 × 23 + 1 × 16
= 46 + 16
= 62
Therefore, the formula mass of Na2O is 62 u.
(ii) Formula mass of Al2O3 can be calculated as follows:
Formula mass of Al2O3 = Mass of two Al atoms + Mass of three O atoms
= 2 × 27 + 3 × 16
= 54 + 48
= 102
Therefore, the formula mass of Al2O3 is 102 u.
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