What Is the Mystery Acid in Test Tube #3?

[ldixon]

I have a question on a pre-lab that I have to do. The question is:

You determine that test tube number 3 is an acid. It is colorless, odorless and has a very low pH value. You test the sample with all eight(8) reactants available and find no reaction(NR). What is the acid? Explain your answer.

The 8 reactants in the lab are:

KOH
AgNO3
BaCl2
NaCl
NH3(aq)
Ba(OH)2
H2SO4
Cu(NO3)2

I could not figure this out, it seems to me that every acid would react with at leat one of these? Is there an acid that would have no reaction with all of these?

 

[Stevedye56]

Start out with what you know is not an acid, then determine which is a notable strong acid and cancel that. this will help you start out

 

[ldixon]

Im not sure what you mean, I don't know what the acid is that has no reaction with all 8 of the listed reactants?

 

[Stevedye56]

do you know what every acid contains in it? if not what about a base? Also does you book give a list of salts?

 

[ldixon]

Yes acids contain H+ and bases contain OH, and yes I think there is a list of salts in the book.

 

[Stevedye56]

im not quite sure what they mean by "low" on the pH scale if low means a low number such as 1 or 2 then its strong, if it means a low number implying that its weak it would be like 6-6.5. Is that exactly what the question reads as written? If so it may be a little more complicated than i originally though

 

[ldixon]

yes low PH means a low number, the problem is written just like that. I can not figure anything out for it.

 

[Stevedye56]

I originally read the problem thinking which one of the given 8 acids/bases/salts were the acid which i knew was easy. Re-reading it however i noticed that you need to know what acid it would be. I did a little searching to help you and came up with this. http://www.wwnorton.com/chemistry/concepts/chapter5/ch5_4.htm

Strong bases= Very good electrolytes

 

[ldixon]

Ok I think it would be HNO3 because it is always soluble with no exceptions, so there would be no visual reaction? Does that sound legit?

 

[Stevedye56]

Yes, that sounds legit to me.

 

[Stevedye56]

Reading over the main question yet another time does it imply that nr is not taking place because nothing visually happened? If so i agree with you.