Question

C7H12 reacts with O2 to produce CO2 and H2O. Suppose 348 g of CO2 are produced in this reaction. What mass of O2 reacted?

Answer 1

398 g

Explanation:

`C_7` `H_16` + 11 `O_2` ------> 7 C`O_2` + 8 `H_2`O

As per the chemical equation for the combustion of
Heptane , `C_7` `H_12` , for burning one mole of Heptane
eleven moles of Oxygen is needed and 7 moles of Carbon dioxide is released.

In terms of mass, 11 moles of Oxygen, ( 11 x 32 g = 352 g ) of Oxygen is needed to produce , 7 moles of Carbon Dioxide,
( 7 x 44 g = 308 g ) of Carbon dioxide is produced.

To produce 348 g of Carbon dioxide, we will need ,

= 352 g of `O_2` x 348 g of C `O_2` / 308 g of C`O_2`

= 397.7 g of `O_2`