Choose from the following list of substances, as to what matches the description given below : [Acetylene gas, aqua fortis, coke, brass, barium chloride, bronze, platinum]
A gaseous hydrocarbon commonly used for welding purposes
An aqueous salt solution used for testing sulphate radical.
A black, powdery substance used for the reduction of zinc oxide during its extraction.
A catalyst used in the manufacture of nitric acid by Ostwald's process.
The substance is an alloy of zinc, copper and tin.