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Question
Write the name of the following compound and deduce its molecular mass.
K2CO3
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Solution
K2CO3 - Potassium carbonate
| Molecule | Constituent elements | Atomic mass u | Number of atoms in the molecule | Atomic mass × number of atoms | Mass of the Constituents u |
| K2CO3 | K | 39 | 2 | 39 × 2 | 78 |
| C | 12 | 1 | 12 × 1 | 12 | |
| O | 16 | 3 | 16 × 3 | 48 |
The Molecular mass of K2CO3 = Sum of Constituent atomic masses
(Molecular mass of K2CO3) = (Atomic mass of K) × 2 + (Atomic mass of C) × 1 + (Atomic mass of O) × 3
= (39 × 2) + (12 × 1) + (16 × 3)
= 78 + 12 + 48
= 138 u
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