Activation energy of bromate/bromide reaction in acidic solution

[sspanzer]

1. given/known data
My work is about calculating activation energy of bromate/bromide reaction.
Besides KBr and KBrO3, phenol and methy red is also used. The Bromine produced react rapidly with phenol, once all the phenol is consumed, the bromine will decolorize the methyl orange indicator. In that way the time for a reaction to reach a certain point can be determined

Homework Equations

BrO3- (aq) + 5 Br- (aq) + 6 H+ (aq) → 3 Br2 (aq) + 3 H2O (l)

My question is, what is the gel-like substances i found at the end of the reaction?

 

[flys]

a guess

I would guess that it is 2,4,6TribromoPhenol : http://chemicalland21.com/specialtychem/perchem/2,4,6-TRIBROMOPHENOL.htm
But then I have a question for you : do you have an experiment guide for the experiment - I found the one from Bangor University, but there is no info about conentrations and so - I would be glad if you could send me a mail if you have it.
best wishes
finn

 

[a.sanders]

concentrations for a 3 min reaction are as follows:
0.01M phenol (0.94g in 1dm³) 70cm³
0.1M KBr (11.9g to 1 dm³) 35cm³
0.02M KBr0₃ (3.34g in 1 dm³) 35cm³
0.5M H₂SO₄ 35cm³

hope this helps

 

[photoelectric]

did you manage to find the activation enthalpy? And when plotting a 1/T against natrual log of rate graph false origins are ok because I only need the gradient?

 

[DeeNos]

I would first like to commend you on your work in calculating the activation energy of the bromate/bromide reaction. It is an important reaction to study in acidic solutions as it has implications in various industrial and environmental processes.

To address your question about the gel-like substances found at the end of the reaction, it is likely a precipitate formed from the reaction between bromine and a phenol compound. This precipitate is often a complex mixture of polybrominated compounds and can vary in appearance depending on the specific phenol used. It is important to note that this precipitate should be handled with caution as it may contain toxic compounds.

In addition, the presence of a gel-like substance at the end of the reaction may also indicate incomplete reaction or side reactions occurring. It would be beneficial to further analyze the gel-like substance to determine its composition and origin.

Overall, the formation of a gel-like substance at the end of the bromate/bromide reaction in acidic solutions is a common occurrence and further investigation is needed to fully understand its properties and implications in the reaction.