Main | 2026Mole ConceptMedium
Question
An oxide of iron contains $69.9\%$ iron, its empirical formula, is :
(Given : Molar mass of Fe and O are 56 and $16\text{ }g{\text{ }mol}^{- 1}$ respectively.)
Ans. (2)
Sol. [Key Concept: Convert the given mass percentages of Fe and O to moles, take the simplest whole-number ratio ($2:3$), giving ${Fe}_{2}O_{3}$.]
| Fe | Oxygen | ||
|---|---|---|---|
| Moles : | $$\frac{69.9}{56}$$ | $$\frac{30.1}{16}$$ | |
| Molar Ratio : | 1 | $$:$$ | 1.5 |
| Molar Ratio : | 2 | $$:$$ | 3 |
Options
A.FeO
B.${Fe}_{2}O_{3}$
C.${Fe}_{3}O_{4}$
D.${FeO}_{3}$
Solution
Sol. [Key Concept: Convert the given mass percentages of Fe and O to moles, take the simplest whole-number ratio ($2:3$), giving ${Fe}_{2}O_{3}$.]
| Fe | Oxygen | ||
|---|---|---|---|
| Moles : | $$\frac{69.9}{56}$$ | $$\frac{30.1}{16}$$ | |
| Molar Ratio : | 1 | $$:$$ | 1.5 |
| Molar Ratio : | 2 | $$:$$ | 3 |
Create a free account to view solution
View Solution FreeMore Mole Concept Questions
16 g of an ideal gas SOx occupies 5.6 L. at STP. The value of x is...A sample of protein was analysed for metal content and analysis revealed that it contained magnesium and titanium in equ...A compound contains 7 carbon atoms, 2 oxygen atoms and 9.96 × 10–24 g of other elements. The molecular mass of compound ...The total number of electrons in one molecule of carbon dioxide is :...Dalton's Atomic theory could not explain which of the following?...