Answer:
#4: 0.89 mol/L #5: 0.36 mol
Step-by-step explanation:
#4: Morality is Moles/ Liters
So take 3.2 mols ÷ 3.6 L = 0.8888... since there are 2 sig figs in the question the answer would round to 0.89 mol/L
#5: to find the number of moles needed, you take the mol/L and multiply that by the volume.
0.89 mol/L ×0.400L = 0.356 mols. the liters cancel out. Since 0.89 has the least number of sig figs your final answer should have 2. which it 0.36 mols.
I hope this helps, good luck!