How does H3O+ and OH- relate to acids, bases, and the pH scale?​

For pure water, the values of [H3O+] and [OH-] are equal and thus their values are both 1.0 x 10-7. If there is an equal amount of acid and base present in any solution, the solution is called "neutral" and the pH of the solution is 7. ... The sum of the pH and pOH must always equal 14.

d.) the average kinetic energy of the gas particles is greater in container b because its particles move faster.

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).