how many moles of sodium are there in 28.4 grams of na2so4?

Question

anonymous · Answer

Find the molar mass of $$\text{Na}_2\text{SO}_4$$Then, divide mass by that molar mass to get the number of moles.

anonymous · Answer

yes but doesn't that give us the moles for Na2SO4? How do we find the amount of moles Sodium has in this case?

anonymous · Answer

There are two atoms of sodium in each molecule of sodium sulfate. Once you have the number of moles of sodium sulfate, multiply by two.

anonymous · Answer

28.4g/142.04g = 0.19999mol. the answer is 0.20mol.

anonymous · Answer

on the page the answer is 0.20mol

anonymous · Answer

Trust your instincts on this. Often the answers in books are wrong. Ask your teacher about this to see if there is a mistake in the book.

anonymous · Answer

ok thanks for your help!