What is the mass percentage composition of potassium in saltpeter, #KNO_3#?

1 Answer
Aug 18, 2017

Answer:

#%K# by mass in #KNO_3="Mass of metal"/"Mass of compound"xx100%#

Explanation:

And thus...............we interrogate the molar masses of the compound, and of potassium.....

#K%=(39.1*g*mol^-1)/(101.1*g*mol^-1)xx100%~=39%#

How did I know the atomic mass of potassium?