JEE Main 20137 April
- Exam
- JEE Main
- Year
- 2013
- Date
- 7 April
- Subject
- Chemistry
- Chapter
- Some Basic Concepts of Chemistry
JEE Main 2013 · 7 April · Chemistry · Some Basic Concepts of Chemistry
Experimentally it was found that a metal oxide has formula M _ 0.98...
Experimentally it was found that a metal oxide has formula . Metal M, is present as and in its oxide. Fraction of the metal which exists as would be:
Options
- A6 . 05\text{%}
- B5 . 08\text{%}
- C7 . 01\text{%}
- D4 . 08\text{%}
Correct answer
D. 4 . 08\text{%}
Step-by-step solution
Consider one mole of the oxide, then
Moles of M = 0.98; Moles of O2- = 1
Let 'x' moles of M are in +3 oxidation state, then Moles of M2+ = 0.98-x
On doing charge balancing we get
(0.98 - x)2 + 3x = 2
Or 1.96 - 2x + 3x - 2 = 0
Or x = 0.04
Moles of M = 0.98; Moles of O2- = 1
Let 'x' moles of M are in +3 oxidation state, then Moles of M2+ = 0.98-x
On doing charge balancing we get
(0.98 - x)2 + 3x = 2
Or 1.96 - 2x + 3x - 2 = 0
Or x = 0.04