Question

Sodium superoxides $Na{O}_2$ can't be prepared directly from sodium, but form $N{a}_2{O}_2$,Then the amount of $N{a}_2{O}_2$ required to prepare 11 g of $Na{O}_2$ is :

• A. 7.2 g
• B. 7.8 g
• C. 3.6 g
• D. 3.9 g

Answer 1

The correct option is B 7.8 g

$N{a}_2{O}_2+O_2\to 2Na{O}_2$.

So 78 grams of $N{a}_2{O}_2$ gave 110 grams of $2Na{O}_2$

How many grams would give 11grams of $2Na{O}_2$?

$78\times 11=110\times x$

$\frac{78\times 11}{110}$= $7.8$

So 7.8 grams is required.
Hence option B is correct.