Find the formula mass of KMnO4

1.	Find the formula mass of KMnO4
Answer» ic mass of: K = 39 U Mn = 55 u O = 16 u Now, KMnO4 = 39 u + 55 u + 4(16 u) = 39 u + 55 u + 64 u = 158 u. ∴ The formula unit mass of KMnO4 is 158 u. More: What is the difference between MOLECULAR mass and formula unit mass? The basic thing is that we use the TERM 'formula unit mass' only when the molecules are formed by ions.

Answer»

ic mass of:

K = 39 U

Mn = 55 u

O = 16 u

Now, KMnO4 = 39 u + 55 u + 4(16 u)

= 39 u + 55 u + 64 u

= 158 u.

∴ The formula unit mass of KMnO4 is 158 u.

What is the difference between MOLECULAR mass and formula unit mass?

The basic thing is that we use the TERM 'formula unit mass' only when the molecules are formed by ions.

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