How many moles of potassium are in 156.4 g of potassium?

Well, darling, if you want to get technical, the molar mass of potassium is approximately 39.10 g/mol. So, if you have 156.4 g of potassium, you simply divide the given mass by the molar mass to find that you have about 4 moles of potassium. But hey, who's counting?