When a mixture of 10 moles of `SO_(2)` and 15 moles of `O_(2)` was passed over catalyst, 8 moles of `SO_(3)` was formed. How many moles of `SO_(2)` and `O_(2)` did not enter into combination?

Options

A. `n_(SO_(2)) = 10, n_(O_(2)) = 10`
B. `n_(SO_(2)) = 10, n_(O_(2)) = 7.5`
C. `n_(SO_(2)) = 2, n_(O_(2)) = 7.5`
D. `n_(SO_(2)) = 4, n_(O_(2)) = 11`

Answer

A

Explanation

`{:(,2SO_(2),+,O_(2),rarr,2SO_(3)),("Initially","20 moles",,"15 moles",,-),("Finally","10 moles",,"10 moles",,"10 moles"):}`