What is periodic table

Label a-f based on the table using c for concentrated and d for dilute

Imagine that twenty i.u.’s of enzyme z were catalyzing the above reaction for one minute, under vmaxconditions, in a 3.00 ml assay volume. the assay is buffered with 20 mm phosphate buffer, ph 7.60. what will the ph be at the end of that one minute?

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?