How many grams of oxygen are in 4.50x10^25 formula units of potassium sulfate? Potassium Sulfate = K2SO4 = 174.252 g/mol

K2 = 78.196 g/mol
S = 32.06 g/mol
O4 = 63.996 g/mol ​

4777.09grams

Explanation:

To find the mass of oxygen, we first need to find the mass of potassium sulfate (K2SO4).

Since there are 4.50 x 10^25 formula units of potassium sulfate, we can find the number of moles in K2SO4 by dividing by Avagadros number (6.02 × 10^23 units). That is;

number of moles of K2SO4 (n) = 4.50 x 10^25 ÷ 6.02 × 10^23

= 0.747 × 10^ (25-23)

= 0.747 × 10^2

= 7.47 × 10^1 moles

Mass in grams of K2SO4 can be calculated thus: molar mass of K2SO4 × moles

= 174.252 g/mol × 7.47 × 10^1 moles

= 13016.62grams.

Since mass of oxygen in 1 mol of K2SO4 = O4 = 63.996 g/mol

We find the percentage by mass of oxygen in K2SO4 as follows:

= 63.996/174.252 × 100

= 0.367 × 100

= 36.7% by mass of oxygen.

This means that in 1gram of K2SO4, there are 0.367gram of Oxygen. Hence, in 13016.62grams (4.50 x 10^25 units) of K2SO4, there will be;

0.367 × 13016.62

= 4777.09grams of oxygen.