Describe the reactions of cis- and trans-K[Cr(C2O4)2(H2O)2] with NH3, and the reverse reactions with HCl using chemical equations. List any observations, such as color changes and apparent solubilities

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.

i think   the answer is c hope i'm right