How many atoms of Oxygen are in 62.63x10^-24 g of C4H9O3?

Round to the hundredths.

How do i complete this electrolysis of water lab? i’m at home, so i don’t have the materials, and the lab didn’t properly work and was incomplete at school.

Ineed to find the answer of this question because i dont understand it

Apump contains 0.5 l of air at 203 kpa.you draw back on the piston of the pump, expanding the volume until the pressure reads 50.8 kpa. what is the new volume of the air pump