6. A crystal of the purple compound potassium manganate (VII) is placed at the bottom
of a beaker of water and the beaker left until there
is no further change. What will be
observed?
A a uniformly purple solution.
B
a purple layer below a colourless layer.
С a colourless layer below a purple layer.
D a deep purple layer below a pale purple layer.
Sec 3/KPT and SMS/2021
Page 2 of 3

I don't know

Explanation:

sorry i just need point to ask so i have comment

the first point, i am pretty sure.

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.