Hydrogen iodide, hi, is formed in an equilibrium reaction when gaseous hydrogen and iodine gas are heated together. if 20.0 g of hydrogen and 20.0 g of iodine are heated, forming 10.0 g of hydrogen iodide, what mass of hydrogen remains unreacted? a. 10.0 g hydrogen remains b. 10.9 g hydrogen remains c. 15.0 g hydrogen remains d. 19.9 g hydrogen remains.

D. 19.9 g hydrogen remains.

Explanation:

To calculate the moles, we use the equation:

a) moles of

b) moles of

According to stoichiometry :

1 mole of require 1 mole of

Thus 0.0787 moles of require= of

Thus is the limiting reagent as it limits the formation of product and acts as the excess reagent. (10.0-0.0787)= 9.92 moles of are left unreacted.

Mass of

Thus 19.9 g of remains unreacted.