what is the observation when methyl orange mix in acetic acid and in sodium acetate in terms of le chateliers

Question

and also what is the observed results when concentrated HCl is added to a saturated NaCl solution someone explain these two questions in terms of Le Chatelier's principle please.

Answer 1

Methyl orange is a weak acid. Let us give it the formula HIn.
It has an equilibrium HIn <-----> H+ + In-
In CH3COOH, there are just enough H+ ions to force this equilibrium to the right, so you see the "acid colour". In CH3COO-, the equilbrium is forced to the left, so you see the "alkaline colour".

When conc HCl is added to saturated NaCl, the concentration of Cl- ions is raised, forcing this equilibrium to the left:

NaCl(s) + aq <------> Na+(aq) + Cl-(aq)

So solid NaCl precipitates. This is called the common ion effect.