Consider the reaction for recovering trace gold when mining: -------Au+---------
ID: 967721 • Letter: C
Question
Consider the reaction for recovering trace gold when mining:
-------Au+---------NaCN+------------O2+----------H2O-------NaAu (CN)2+----------------NaOH
a)Balance the reaction
b)What is the molecular mass of sodium cyanide (NaCM)?
c)How many sodium hydroxide molecules are generated when four atoms of gold (Au) react?
d)If you used 2 moles of O2 when the reaction is complete, how many moles of sodium hydroxide ( NaOH ) did you generate?
e)If four moles of O2 reacted, how many grams of gold reacted with it?
Explanation / Answer
a) 4Au+8NaCN+O2+2H2O4NaAu (CN)2+4NaOH
b) molecular mass of NaCN =(23+26)=49g/mol
c) 4 molecules
d) 8 moles
e) 16 moles