Which type of reaction forms water from hydrogen and oxygen atoms? double-replacement reaction synthesis reaction decomposition reaction single-replacement reaction?

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.

its first and third is your answer i did the qustion the fourth isnt right

so she was walking and she stepped on warm jeffy , uh uh uhh dadye i just pooped my pants