To balance an equation, what should you never change?

To balance a chemical equation, you can't change the subscripts. If you change or mess around with the subscripts, you may be balancing the equation but it's no longer the equation that you are are dealing with.

So as a rule, you can't modify any of the subscripts.

vanderwaal's forces of attraction are the electrostatic intermolecular forces that exist in a molecule due to the temporary or permanent dipoles that are developed in a molecule. in , the major intermolecular forces are dipole-dipole interactions as the molecule is polar (bent structure). so the vanderwaal's forces of interaction in between molecules are the permanent dipole-dipole interactions that develop due to the dipole that exists in between the polar h - s bond. the positively charged hydrogen atom is attracted towards the negative end of the dipole that is sulfur of the adjacent molecule. therefore, these forces of attraction are relatively stronger than that of london dispersion forces that exist in non polar molecules.

the ratio of the conjugate base to the acid required to attain the desired ph.