Question

Silicon tetrachloride (`SiCl_4`) can be prepared by heating `Si` in chlorine gas: `Si (s) + 2Cl_2(g) -> SiCl_4(l)`. In one reaction, 0.507 mole of `SiCl_4` is produced. How many moles of molecular chlorine were used in the reaction?

Answer 1

Stoichiometry demands at least `1.14` `mol` of `Cl_2` gas.

Explanation:

The stoichiometric equation, which you have correctly written, clearly and explicitly shows that `1` `mol` of silicon (approx. `28*g`) reacts with `2*"moles"` of chlorine gas (approx. `71*g`) to give `1` `mol` of `SiCl_4`.

The equation establishes both the molar and mass balance.