Answer:
Hi there!
The correct answer is 2.29 x
molecules
Explanation:
To convert from the moles to molecules:
1 mole = 6.022 x 10²³ molecules
so basically you multiply 3.8 by 6.022 x 10²³
and you get: 2.29 x 
Here you go! There are 0.9307 moles in 123.0 g of the compound. I solved this by using a fence post method. I calculated the number of grams in one mol of (NH4)2 SO4 and got 132.16.
I did this by finding the atomic mass of each element on the periodic table (my work is in the color blue for this step)
After that, i divided the given mass by the mass of one mol of the compound.
The answer is 0.9307 moles!! I hope this helped you! :))
Common denominator - Find the Least Common Multiple of the denominators (which is called the Least Common Denominator).
Change each fraction (using equivalent fractions) to make their denominators the same as the least common denominator.
Then add (or subtract) the fractions, as we wish!
Least common denominator - You do the same thing for the common denominator