I've never heard of a way that produces HCl only by explosion. Every method I've heard doesn't involve catalysts and at the same time without explosion

Why do you want HCl? Go for Sulphuric acid (its early in the morning, I cant remember the formula) its alot more fun and more concentrated if your just playing with stuff

aj3001, if you are going to help say something helpful.

but in fact HCl is commercially available

Catalysts are used for creating reactions that otherwise wouldn't go, as in 2 SO₂ + O₂ > 2 SO₃; its real easy to burn S into sulfur dioxide but a bitch to get sulfur trioxide under normal conditions, but a platinum mesh burns the dioxide right up into the trioxide which is combined with H₂O for sulfuric acid. Because H₂ + Cl₂ > 2 HCl goes like a bat out of hell (that's the explosion!) no one would search for a catalyst for that reaction. In point of fact, the explosion occurs in the presence of light; if you shield the H₂ and the Cl₂ from light the reaction proceeds rather slowly.

This was a famous lab demo back when Europe was covered by ice sheets; the shielded bottle (encased in mesh) was suspended and then the shield was dropped, and voila, when the light (probably the blue end of the spectrum) hit the H and Cl mixture, BOOM! I take it chem students don't see as many explosive lab demonstrations these days.

Since a catalyst is used to increase the rate of a reaction, you are actually looking for an inhibitor, a substance that decreases the rate of a reaction. These are usually those noxious chemicals they put in your bologna "to maintain shelf freshness"; I believe phthalic acid is put in H[/sub]2_O2 _{to keep the peroxide from decomposing as rapidly as it would otherwise do, but since no one in his right mind would ever store a mixture of H}2 _{and Cl}2[sub], I don't know of any inhibitor that is used for this reaction.

It may have been helpful depending on your application of this acid, if you want something helpful:
Scientific & Chemical: Laboratory Equipment and Chemicals 2004 catalogue: Page C60, 2.5l of 5molar HCl £12.48

What does 1 molar mean

molar is a basic term in chemistry to describe the concentration of substances in (aqueous) solution. A 1 molar solution contains 1 mole(cular weight) of substance dissolved in 1 liter of total solution; 1 molal is one mole in 1 liter of solvent.

thanks aj3001

then how heavy is 1 mole