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Calculate the number of moles in 46 g of sodium. (Atomic mass of Na = 23)
A0.5 mole
B1 mole
C2 moles
D4 moles
Answer & Solution
Correct answer: C. 2 moles
1. Number of moles $= \dfrac{\text{mass}}{\text{atomic mass}}$.
2. $= \dfrac{46}{23}$.
3. $= 2$ moles of sodium.
If you wrongly multiplied instead of dividing you would get 1058, which is not a sensible mole count.
_Source: Samacheer Kalvi (TN SCERT) Class 10 Science, Unit 7 Atoms and Molecules "Solved Problems", p.106_
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