Can matter be categorized by weather it’s a pure substance or mixture?

Explanation:

Matter can be broken down in two categories by pure substance and mixtures. Pure substance are further broken down into elements and compounds. Mixtures are physical combined structures that can be separated into their original components.

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.