Why Water Is Excellent Solvent With Polar Substance?


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Katie Harry answered
Sakriya, you might be familiar with the word 'dipole'. It is a molecule in which the two atoms comprising it have a huge difference in their electronegativity as in this case between hydrogen and oxygen. This makes the water molecule highly polar. This gives the molecule a positively charged end and a negatively charged end.
Now, you must also know that opposites attract. So, when a polar substance is added to water, water molecules surround it in such a way that the negative ends of the water molecules align with the positive ends of the solute molecules and vice versa. Since water molecules are so small, they often completely surround the solute molecules, thus resulting in very good solibility.
Let's discuss this with an example. Imagine you put in some copper sulphate in a beaker full of water. As soon as the solute (copper sulphate) enters the solution, it dissociates into copper(II) ions and sulphate ions. Copper ions are positively charged and sulphate is negatively charged. So, water molecules will surround copper ions with their negative ends towards it. Around the sulphate ions, they will point their positive ends. The solution turns blue as copper is incorporated into it, i.e. It dissolves and no solid particles of it remain.

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