Check wether all the answers are correct or not. please?

What is the ph of a solution with a 1.50 × 10−9 m hydroxide ion concentration?

Which statement describes james chadwick’s discovery.

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?