posted by tg .
To extract gold from its ore, the ore is treated with sodium cyanide solution in the presence of oxygen and water.
4 Au(s) + 8 NaCN(aq) + O2(g) + 2 H2O(l) 4 NaAu(CN)2(aq) + 4 NaOH(aq)
Determine the mass of gold that can be extracted if 27.4 g sodium cyanide is used.
If the mass of the ore from which the gold was extracted is 157.0 g, what percentage of the ore is gold?