In the hydrogenation of oils the catalyst used is:
A. Pt
B. Ni
C. Fe
D. V2O5

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.

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements

the answer is:  

line graphs show patterns in data with variables that change over time; whereas, circle graphs show data as parts out of a whole (such as out of 100%).