I need help is something I do not understand

Idon't really understand this can you me and show your work.☺☺[ chemistry b] subject [ electron transfer in lonic bonds]grade( 12)

What is the mass of 4 molecules of co2

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?