When a voltaic cell changes to begin operating as an electrolytic cell,

A. the positive electrode changes from being the cathode to being the anode.
B. the negative electrode becomes both the anode and the cathode.
C. the positive electrode changes from being the site of oxidation to being the site of reduction.
D. the negative electrode becomes the site of both oxidation and reduction.

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.

the answer is c

tell me if wrong