If 0.720 mol of gaseous Cl2 and 390 mL of 0.641 M aqueous NaBr are reacted stoichiometrically according to the balanced equation, how many moles of gaseous Cl2 remain? Round your answer to 3 significant figures.

2NaBr(aq) + Cl2(g) → 2NaCl(aq) + Br2(l)

3 answers

You know the amount of Cl2. You can find the moles NaBr from M x L = moles. From that you can calculate the amount of NaBr and Cl2 used and from that the amount of either of the reactants in excess. Show your work if you get stuck.
Thanks, i figured it out using the mol ratios of NaBr and Cl2.
Way to go.