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Question
Write the name of the following compound and deduce its molecular mass.
NaOH
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Solution
NaOH - Sodium hydroxide
| Molecule | Constituent elements | Atomic mass u | Number of atoms in the molecule | Atomic mass × number of atoms | Mass of the Constituents u |
| NaOH | Na | 23 | 1 | 23 × 1 | 23 |
| O | 16 | 1 | 16 × 1 | 16 | |
| H | 1 | 1 | 1 × 1 | 1 |
The molecular mass of NaOH = Sum of Constituent atomic masses
(Molecular mass of NaOH) = (Atomic mass of Na) × 1 + (Atomic mass of O) × 1 + (Atomic mass of H) × 1
= (23 × 1) + (16 × 1) + (1 × 1)
= 23 + 16 + 1
= 40 u
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