+128475 7.2 = - log (H).....multiply both sides by -1
-7.2 = log (H) and we can write
10-7.2 = H ≈ 6.3 x 10-8
log, or logarithm, is an operation. It is in the same category as a multiplication or addition. Logistically, the question you asked doesn't really make sense as it would be in the same line as asking, "what is 7.2 divided by a multiplication sign?"
What we're looking for here is the concentration of protons (H+) or more accurately hydronium ions (H3O+). A pH of 7.2 says that your solution is 10^(-7.2) molar H3O+. A pH of 13.1 would mean your solution is 10^(-13.1) molar H3O+.
Logarithms are operators saying "to what number must your base be raised to achieve a number?" For instance, another way of writing 10^x = 1000 is writing log10(1000) = x, where x = 3. Exponentials and logarithms are like additiion/subtraction or multiplication/division. They are inverse operators.
So, that means in order to know the concentration of H+ or H3O+, we can multiply both sides by negative one and exponentiate 10^(-7.2) to learn the molarity.
If anything I said was unclear, please let me know.
Cheers.
