In the first reaction, they must change the stoichiometric coefficient so that the reaction is balanced.

Sulfuric acid can be obtained as a by-product of the extraction of zinc from its sulfide ores. Mineral analysis indicates 65.0%ZnS and 35% inert impurities by weight. The ore is roasted in a kiln to which a 1220kmol/h air stream (composition 79%N2 and 21% 02) is fed and the resulting SO2 is converted to SO3 in a catalytic reactor. The SO3 is absorbed in water to form sulfuric acid, the final product being 2.0% water and 98%H2SO4 by weight. A total of 99.0% of the sulfur in the ore is recovered in the acid. ZnS+21O2ZnO+SO2SO2+21O2SO3SO+H2OH2SO4 (For these questions, consider the 186 tons of minerals per day.) 1. In the furnace what is the limiting reagent and the excess reagent? What is the percentage in excess fed? 2. Calculate the mass of sulfuric acid ( 98%H2SO4 and 2%H2O by weight) produced per hour in a zinc plant processing 186 metric tons of ore per day (assume 8 hours of operation). 3. What amount of water in kg is consumed in one hour? 4. How many kg/h of mineral remain unreacted