Galena (an ore) is partially oxidized by passing air through it at high temperature. After some time, the passage of air is stopped, but the heating is continued in a closed furnance such that the contents undergo self-reduction. The weight (in kg) of Pb produced per kg of O2 consumed is ______ . (Atomic weights in g mol–1 : O = 16, S = 32, Pb = 207)
