Acid calcs

[Jblyth]

I'll start this thread my admitting my inability to perform what seems like basic math and I would like to know if i'm coming up with the correct numbers for TA.

I have a basic acid kit where you take a 15ml sample of wine and you're supposed to add 3 drops of reagent (forget the solution name), then add Sodium Hydroxide (?) a ml at a time swirling to see if the color changes. Since I'm testing against a deep red wine, the instructions called for dilution of 15ml of water (which I did). In total, I ended up adding 13.5ml of Sodium Hydroxide to the wine before the color changed to a deep black/blue color.

My question is this: What is my Total Acid? Since I diluted, do I multiply by 2x or divide by 2x?

Thanks!

 

[Julie]

Well to be honest I am probably not going to be much help but this is what I did when using a tritation kit. I used 10ml of must and when the color changed I would multiply how much I used by .75. I would do this even if I added 10ml of water to lighten the must. Example would be, 12ml of solution x .75 = .90% acid.

I have no idea if this would be correct with 15ml. And I now just use a ph meter. Did you get an instruction pamphlet?

 

[Jblyth]

The instructions stated that reds should be diluted to better see the color change, but didn't supply the math to go along with the dilution :-(

In Non-diluted, the amount of sodium hydroxide added equals the acid level, so my puny little brain is saying divide by 2 but not sure that's correct?

 

[GreginND]

The instructions stated that reds should be diluted to better see the color change, but didn't supply the math to go along with the dilution :-(

In Non-diluted, the amount of sodium hydroxide added equals the acid level, so my puny little brain is saying divide by 2 but not sure that's correct?

No correction is needed. Diluting with DI water does not change the number of acidic protons. The titration will be the same. It is total acid not pH (acid strength) you are measuring.