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Question
Calculate the formula masses of the following compounds :
Calcium carbonate
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Solution
Atomic mass of aluminium = 27 u
Atomic mass of oxygen = 16 u
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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