Final answer:
To find the mass of diethylamine needed, multiply the volume of 80.0 mL by the density of 0.706 g/cm³, resulting in a mass of 56.48 g to be weighed out for the experiment.
Step-by-step explanation:
To calculate the mass of diethylamine the student should weigh out, you need to use the density of diethylamine which is 0.706 g/cm³. The volume needed is 80.0 mL (which is equivalent to 80.0 cm³ since 1 mL = 1 cm³). By multiplying the density by the volume, you will get the mass.
The formula to calculate mass based on density is: Mass = Density × Volume.
So, the calculation would be: 0.706 g/cm³ × 80.0 cm³ = 56.48 g.
Therefore, the student should weigh out 56.48 g of diethylamine for the experiment.