What is the ph of a very acidic solution?

pH = -1

Explanation:

A solution of 10 mol·L⁻¹ HCl is very acidic.

HCl is a strong acid, so it dissociates completely in water and

To get the pH, you take the negative logarithm of the hydronium ion concentration.  

So, a pH = -1 represents a very acidic solution.

answer: the rate of diffusion increases with increase in temperature.

increase in temperature, increases the molecular/particles speed (kinetic energy. diffusion means movement of particles through the material.

generally, the heavier the particle the more it interacts with the environment and more the temperature matters. so higher temperature results in higher diffusion.

they are made of gases.

they have a spherical shape.

they make energy through fusion.