Recently, I was studying about oxyacids and my teacher took example of a general compound $\ce{X-O-H}$. He told that that on dissolving it into water ,water would break apart either $\ce{O-H}$ bond or $\ce{X-O}$ bond depending upon the electronegativity difference and hence they would be called an oxyacid or oxobase.
But I want to know whether water would also separate the remaining part as the left out atoms also have electronegativity difference in $\ce{X-O}$ and $\ce{O-H}$. Is the explanation hidden in negative charge of remaining part? If not why?