Question

A chemist working as a safety inspector finds an unmarked bottle in a lab cabinet. A note on the door of the cabinet says the cabinet is used to store bottles of diethylamine, ethanolamine, tetrahydrofuran, acetone, and carbon tetrachloride. The chemist plans to try to identify the unknown liquid by measuring the density and comparing to known densities. First, from her collection of Material Safety Data Sheets (MSDS), the chemist finds the following information: liquid density diethylamine ethanolamine tetrahydrofuran acetone carbon tetrachloride Next, the chemist measures the volume of the unknown liquid as and the mass of the unknown liquid as . Calculate the density of the liquid. Be sure your answer has the correct number of significant digits. Given the data above, is it possible to identify the liquid? yes no If it is possible to identify the liquid, do so. diethylamine ethanolamine tetrahydrofuran acetone carbon tetrachloride

Answer 1

For the following:

• Yes, it is possible to identify the liquid.
• The most likely liquid is ethanolamine.

How to determine density?

Calculating Density and Identifying the Liquid

1. Density Calculation:

Volume (V) = 24.5 mL (from measurement)

Mass (m) = 28.95 g (from measurement)

Density (ρ) = m/V

= 28.95 g / 24.5 mL

≈ 1.18 g/mL (round to 3 significant digits)

2. Identifying the Liquid:

Now, compare the calculated density (1.18 g/mL) with the densities from the MSDS sheets:

Diethylamine: 0.70 g/mL

Ethanolamine: 1.02 g/mL

Tetrahydrofuran: 0.88 g/mL

Acetone: 0.79 g/mL

Carbon tetrachloride: 1.59 g/mL

Therefore, the unknown liquid is most likely ethanolamine because its density (1.02 g/mL) is closest to the calculated density (1.18 g/mL) compared to the other options.