Guys just a really easy question i need clarification with..
How many moles of O-atoms in 25.7g of CaSO4?
I know moles = mass/molar mass
25.7/(40.8 + 32.07 + 4x16) = .188
Is this the answer or do i multiply .188 by 4 because there is 4 oxygen atoms in CaSO4?
How many molecules in 13.72g oh hydrazine? N2H4? i dont even know where to start!
If anyone could help me at all it would be much appreciated!