Which of the following salts will be less soluble in 0.10 M NaCl than it is in pure water? PbF2

CaCO3

All of the options are less soluble in 0.10 M NaCl than in pure water.

PbCl2

The less soluble salt : PbCl₂

Given

0.1 M NaCl

Required

The less soluble salt

Solution

If we see from the answer option, the salt that is more difficult to dissolve in NaCl is PbCl₂ because it has the same ion (Cl)

When PbCl₂ is dissolved in water, ionization will occur

PbCl₂ ⇒ Pb²⁺+ 2Cl⁻

So, when dissolved in NaCl, NaCl itself will be ionized

NaCl ⇒ Na⁺ + Cl⁻

Based on the principle of equilibrium, the addition of an ion (one of the ions is enlarged), the reaction will shift towards the ion that was not added. In addition to this Cl ion, the reaction will shift to the left so that the solubility of PbCl₂ will decrease (the reaction to the right decreases)

it means there are 3 atoms of oxygen