40.2 grams of Hydrogen Chloride (HCl) is decomposed. 12 grams of Chlorine (Cl) is formed. How many grams of Water (H2O) was formed?

3.05 g

Explanation:

The reaction that takes place is:

As the decomposition not necessarily was complete we'll work with the given mass of product formed. We convert the 12 grams of chlorine to moles, using its molar mass:

Then we convert Cl₂ moles to H₂O moles:

Finally we convert moles to grams:

if the concentration of products is decreased, the equilibrium will shift toward the products). add an inert gas (one that is not involved in the reaction) to the constant-volume reaction mixture: this will increase the total pressure of the system, but will have no effect on the equilibrium condition.

explanation:

i think   the answer is c hope i'm right