The B atom in BCl3 has only six electrons in the valence shell and hence is an electrondecient molecule. It easily accepts a pair of electrons donated by water and hence BCl3 undergoes hydrolysis to form boric acid (H3BO3) and HCl.
BCl3 + 3H2O → H3BO3 + 3HCl
In contrast, C atom in CCl4 has 8 electrons in the valence shell. Therefore, it is an electron-precise molecule. As a result, it neither accepts nor donates a pair of electrons. In simple words, it does not accept a pair of electrons from H2O molecule and hence CCl4 does not undergo hydrolysis in water.
