Five grams of sodium are combined with unlimited bromine. How many moles of bromine are used up? How many liters of bromine would be used if the reaction took place at STP?

My answer:
.1088 mole Br2 and 2.44 L Br2

1 answer

If that is 5 g then you have only one significant figures so the answer is 0.1 and you're correct. However, the second part can't be done that way. You have assume, I suppose, that Br2 is a gas and it occupies 22.4 L/mol. If that were true your answer of 2.44 would be ok BUT Br2 is not a gas at STP. I think the author of the problem screwed up. If you look up the density of liquid Br2, then mass = volume x density. With the density and the mass you could calculate the volume.