(c) amphoteric oxide (d) basic oxide 9. Which of the following compounds is not a double salt? (a) Zn (OH) NO3 (b) KAI (S04)2 (c) KСr (S04)2 (d)
(NH4) Fe (S04)2
. Which of the following decreases in mass on exposure to air? (a) NaOH (b) Fe (c) FeCl3 (d) Na2C03.10H20
The laboratory apparatus used in keeping salts is​

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.

they are both synthetic elements

explanation:

d