Question

How many molecules are in 25g of Na2SO4? POINTS!! Please help! Im so frustrated.

Answer 1

Hey there!

Molar mass Na2SO4 = 142.04 g/mol

Number of moles:

n = m / mm

n = 25 / 142.04

n = 0.176 moles of Na2SO4

Therefore, use the Avogadro constant


1 mole Na2SO4 ------------------- 6.02x10²³ molecules
0.176 moles Na2SO4 ------------   molecules ??


0.176  x  ( 6.02x10²³ ) / 1 

=> 1.059x10²³ molecules of Na2SO4

hope this helps!