Why is Leslie's Brand Muriatic Acid Yellow?

[SunnyOptimism]

I've procured MA from many different sources - Ace Hardware, Leslie's, Patio Pools, etc, and it is only the Leslie's brand that I find being a strong yellow color. I know MA can have by-product from production in it that can make it a pale, straw yellow but this stuff from Leslie's is a VIBRANT yellow. When I did lab work with reagent grade HCl (back in my working days), it was always clear.

Do they dye it for "safety" or is it truly contaminated with something?

It works just fine at lowering the pH and is always on the money in terms of pH change as calculated. Just wondering what they use to make it so yellow.

[SunnyOptimism]

BUMP

(Sorry Mods, I should have posted this question in the Subscriber Forum. My Bad!!!)

[kelemvor]

I don't have an answer, but I'm curious as well.

[SunnyOptimism]

I'm really hoping that Leslie's is using a safety colorant in their HCl as opposed to this coming from trace impurities The color is vibrant yellow and commercial grade HCl is usually just a pale straw yellow to slightly greenish yellow when iron (Fe3+) or free Cl2 gas is present.

One method of production is by the following reaction -

H2SO4 + 2 KCl --> K2SO4 (s) + 2 HCl (gas)

The gaseous HCl is then drawn off and typically absorbed in a fluid bed to make a concentrated aqueous solution. Reagent grade HCl is then made from this feed stock by further purification techniques to remove iron salts (pale straw yellow).

Considering how vibrant yellow the Leslie's product is, either they are selling contaminated garbage (I'd really hope not but wouldn't put it past them) or they are coloring the MA for safety.

I had hoped someone on the Forum would know for sure. If not, I'll try their customer service at some point to see if they have an answer.