Question

Hm many grams of `CO_2` would be formed from 30 grams of `C_7H_8` in the following reaction `C_7H_8 + O_2 -> CO_2 + H_2O`?

Answer 1

Approx. `100` `g`.

Explanation:

A balanced equation representing the complete combustion of toluene is absolutely necessary:

`C_7H_8 + 9O_2 rarr 7CO_2 + 4H_2O`

This tells us that for every mole of toluene, 7 moles carbon dioxide gas are evolved under conditions of complete combustion. So we need to find (i) molar quantity of toluene, and (ii) equivalent molar quantity of carbon dioxide.

Moles of `C_7H_8` `=` `(30*cancelg)/(92.14*cancelg*mol^-1)` `=` `0.326` `"mol"`

Given the stoichiometry of the rxn, 7 mol carbon dioxide are produced from 1 mol toluene. Thus, the answer is:

`7` `xx` `44.0` `g*cancel(mol^-1)` `xx0.326` `cancel(mol)` `=` `??g`

If `1` '`mol` of gas occupies `25.4` `dm^3` under standard conditions, what is the volume of this molar quantity of `CO_2`?