Because they are good at their professions
Baking soda. to put in the most simple terms..
-OH is the "base" anion
H+ is the "acid" ion
It can be easily judged that only the first reaction is an acid base reaction among the three given in the question. So, we can avoid the other two reactions given in the question. Now let us focus and write down the balanced chemical equation of <span>P-Toluidine + HCl.
</span><span>C7H9N + HCl = C7H10N (+) + Cl (-)
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I hope the answer has come to your help.