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hey studying for chemistry and need help please

solid alanine is dissolved in water and the sol is divided into two equal portions. Acid is added to one portion to attain a pH of 2. An alkali is added to the other portion to attain a pH of 13.
(i) write the equation for the reaction which takes place in the acidic solution. (ii) write the equation for the reaction which takes place in the alkaline solution.
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1.

solid alanine is dissolved in water and the sol is divided into two equal portions. Acid is added to one portion to attain a pH of 2. An alkali is added to the other portion to attain a pH of 13.
(i) write the equation for the reaction which takes place in the acidic solution. (ii) write the equation for the reaction which takes place in the alkaline solution.

Hi,

Amino acids are AMPHOteric (Greek ampho = both so both acidic and alkaline AS IN AMPHIbian [can live in BOTH water and on land like frog])

The -COOH group is the acidic one; the NH2 group is basic.

ADDING ACID: (the NH2 group reacts with the H+ of the acid): H2NCH(CH3)(COOH) + H+ gives H3N+CH(CH3)COOH (the plus after the H3N is a residual charge on the amino group produed by adding a proton (H+).

ADDING ALKALI: (the COOH group [acidic] is neutralized by the OH- of the alkali to give: H2NHCH(CH3)COO- + H2O.

the salts formed will depend on which acid and alkali are used. 1. There will be an anion (e.g. SO4(2-) if sulphuric acid were added)
2. There will be a cation e.g. K+ if potassium hydroxide was the alkali added (KOH)

M (Science tutor)

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