HCl/HBr salt test

[sekio]

Explain. Theres only a single amino group thats protonated in each salt, so the same amount of base is required to free the base.

One mole of 2CB hydrochloride will have a different mass than one mole of the hydrobromide. Of course you'll still only use 1 molar equivalent of base, but the HBr salt will have a higher molar mass and hence 1 gram of the HBr will contain proportionally more acid and less alkaloid than one gram of the HCl salt.

2C-B = 260.13 Da
HCl = 36.5 Da
HBr = 80.9 Da

so the molar mass of 2CB-HCl is 296.63 g/mol, and the HBr is 341.03 g/mol.

That means in one gram of 2cB HCl there's 3.37 millimoles of alkaloid, and in one gram of 2cB HBr there is 2.93 millimoles. So the HCl will need about 15% more base to titrate to neutrality.

 

[atara]

Do you have anything to support the comment about HCl smoking? DXM.HBr smokes readily.

Do you mean just for 2C-B?

Could silver nitrate be of any use for detecting HCl salts?

It will precipitate with any halide, you might be able to test the precipitate afterwards somehow, but it is not a test per se.

Succinate is a strange one. I think calcium succinate may be insoluble.