I am struggling with this question the answers of the books are different. Can someone help me with this?
The mass of quartz is of no interest. The important question is: how much gold is present? The chemical reaction is: 4 Au + 8 NaCN + O2 + 2 H2O → 4 Na[Au(CN)2] + 4 NaOH (1 g Au) / (196.9665694 g Au/mol) x (8 mol NaCN / 4 mol Au) x (49.00727 g NaCN/mol) = 0.5 g NaCN So for each gram of gold you need 0.5 gram of sodium cyanide. (If you use potassium cyanide instead, the amount needed is closer to 0.7 gram.) In order to find the amount of cyanide for each kg of quartz you need to know how much gold is contained in each kg of quartz. That is, you need to have your quartz assayed. Most importantly: If you must ask this question on YA, you don't have enough experience to be fooling around with cyanide. You are likely to kill yourself. Leave the cyanide alone.
