What is the platinum reaction with hydrochloric acid?

There isn't any with only [math]HCl[/math]. Platinum is a fairly inert material, due to its very high oxidation potential, even more inert than gold. read more

The initial reactions produce a mixture of chloroplatinous acid (H2PtCl4) and nitrosoplatinic chloride ((NO)2PtCl4). The nitrosoplatinic chloride is a solid product. If full dissolution of the platinum is desired, repeated extractions of the residual solids with concentrated hydrochloric acid must be performed. read more

Hydrochloric acid (HCl) reacts readily with most metals other than those in the platinum group in the periodic table. Generally, the metals at the far left of the periodic table react most strongly, and as you progress towards the right side, reactivity lessens. read more