Colors of Acid's

[fulltiltjoke]

Heres the Question:

Two weeks ago i separated two glass 1000ml beakers. One contained Hydrocloric Acid, and one contained Nitric Acid. Unfortunately I forgot to label them.

One is completely clear.

The other has a red tint or hue.

Can anyone identify which is which for sure.

Thanks for the help.

 

[kernels]

Surely a tiny bit of copper and a drop from each beaker will give you the answer ?

 

[Topher_osAUrus]

If i were a betting man, I'd guess the red tint is nitric
But, to be sure
Take a couple ml from each one, putting in their own respective test tube, then add a small piece of copper to each.
Nitric will quickly get to work on it.

The reddish tint, is most likely the NO2 coloring the nitric. Assuming no metals have been dissolved in either questionable acid

Edit: looks like kernals beat me to it, but, if you have no copper, aluminum will also work, but in opposite effect.
HNO3 wont eat it all up, HCl will

Be sure to label, else things can get easily flip flopped

 

[g_axelsson]

My nitric acid is clear as water while my hydrochloric acid is yellowish.

A little contamination can change the color a lot. Don't rely on color, test it as kernels suggested.

Göran

 

[Topher_osAUrus]

My nitric acid is clear as water while my hydrochloric acid is yellowish.
Göran

The yellow is dissolved oxygen, correct?

 

[fulltiltjoke]

Thanks for the help!

I will test tomorrow and let you know the outcome!

 

[4metals]

Depending on the grade Nitric goes from crystal clear to brownish (red?)

Hydrochloric, goes from clear to yellow to green and I always assumed it was iron.

But I would not go by color alone, especially when it is so easy to check.

 

[goldsilverpro]

Like 4metals, I always heard and assumed that yellow in HCl was iron. 67% Nitric is about 20% heavier than 32% HCl. However, like some others said, a drop or two on some clean copper wire or copper pipe is the simplest test.

 

[fulltiltjoke]

Nitric was red. Threw a little copper in there as suggested. Some smoke and super clean copper. TY Everyone.