what's up guys this is Massey welcome to my channel in this video I want to show you how to write their molecular formula for potassium permanganate so I start with potassium potassium is K k plus permanganate is the polyatomic ion and the formula for that is M + o 4 which is negative 1 the charge is negative 1 so when you combine them is kmno4 now if you want to find the molar mass you need to list all the elements and find out the atomic mass from periodic table 39 point oh 9 8 MN is 54 point nine three eight and oxygen is fifteen point nine nine nine how many atoms of potassium we have just one and then we have just one oxygen is four so that's gonna be the same here is gonna be the same and then four times fifteen point nine nine nine makes it sixty three point nine ninety six and then you need to add them all that makes it 150 8.03 to grams per mole that's the molar mass of potassium permanganate I hope you enjoyed this video please leave me a comment if you have any question and I get back to you as soon as I can and please don't forget to subscribe this channel thank you