Easy MCQ +4 / -1 PYQ · JEE Mains 2020

On combustion of Li, Na and K in excess of air, the major oxides formed, respectively, are :

  1. A Li<sub>2</sub>O, Na<sub>2</sub>O<sub>2</sub> and K<sub>2</sub>O
  2. B Li<sub>2</sub>O<sub>2</sub>, Na<sub>2</sub>O<sub>2</sub> and K<sub>2</sub>O<sub>2</sub>
  3. C Li<sub>2</sub>O, Na<sub>2</sub>O<sub>2</sub> and KO<sub>2</sub> Correct answer
  4. D Li<sub>2</sub>O, Na<sub>2</sub>O and K<sub>2</sub>O<sub>2</sub>

Solution

4Li + O<sub>2</sub> $\to$ 2Li<sub>2</sub>O <br><br>2Na + O<sub>2</sub> $\to$ Na<sub>2</sub>O<sub>2</sub> <br><br>K + O<sub>2</sub> $\to$ KO<sub>2</sub>

About this question

Subject: Chemistry · Chapter: s-Block Elements · Topic: Alkali Metals

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