Question

You work in an industrial lab (no TA) that tests soil samples for heavy metals. When you came in to your lab today, there was some white solid that had been spilled on your workbench. Looking at the solid, you notice the solid appears to be a mixture of at least two compounds since there are some small opaque crystals as well as some fluffy powder in the mixture. The company for which you work has strict policies about chemical waste disposal. - all solids must go in specially marked containers, not in regular trash; - water soluble, neutral and non-toxic chemicals can go down the drain with lots of running water; - acidic or basic water-soluble compounds must be dissolved and neutralized before pouring the solution down the drain; - organic and other non-soluble compounds go into specially marked containers; - flammable compounds go into a flame- and explosion-resistant container. Over to the right of the spill are a number of containers that have been used recently. These containers contain chemical compounds, in solid form, that are commonly used in your lab. They are: barium nitrate, sodium chloride, potassium nitrite, iron(III) chloride, sucrose, magnesium carbonate, lithium sulfite, naphthalene, potassium permanganate, lead(II) chloride, copper(II) bromide, calcium sulfate. 1. Thinking the solid is a mixture of chemicals that are commonly used in your lab, you need to test the mixture to see which method of waste disposal is correct. Design a flowchart to test the solid mixture to determine what it might contain. The flowchart must clearly state the chemicals needed for each test as well as show the expected test results.

Answer 1

Identification and separation of compounds in a mixture

1) Add diethylether to the mixture.

2) The organic compounds dissolves in the diethylether layer and the inorganic stays out.

3) Separate the organic layer from insoluble solids.

4) Dispose organics in the organic container waste bottle.

5) The inorganic solids are then treated with water.

6) The water soluble salts and insluble salts are separated.

7) The water soluble and insoluble salts are then disposed in their respective waste containers.