How many milligrams are in 0.2 decigrams?
(a) 20 milligrams
(b) 2000 milligrams
(c) 0.002 milligram
(d) 0.2 milligram

There are 20 milligrams in 0.2 decigrams

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.