Lead can be prepared from galena [lead(II) sulfide] by first roasting the galena in oxygen gas to form lead(II) oxide and sulfur dioxide. Heating the metal oxide with more galena forms the molten metal and more sulfur dioxide.
(c) How many metric tons of sulfur dioxide form for every metric ton of lead obtained?
There are two reactions described in this problem and both get a product of sulfur dioxide SO2.
The first reaction is the reaction of Galena and oxygen to produce sulfur dioxide and lead (II) oxide. The balanced reaction is shown below.