Give one reason why we cannot reuse boiling chips?

What additive may lower the electrical resistance in a plastics?

A student is given a sample of red cobalt sulfate hydrate. She weighed the sample in a dry covered crucible and obtained a mass of 25.050 g for the crucible, cover, and sample. Before adding the sample, the crucible and cover weighed 23.422 g. She then heated the crucible to drive off the water of hydration, keeping the crucible at red heat for about 10 minutes with the cover slightly ajar. She then let the crucible cool, and found it had a lower mass; the crucible, cover and contents then weighed 24.321 g. In the process the sample was converted to blue anhydrous CoSO,. Show all calculations necessary to answer the following questions. 1. What was the mass of the hydrate sample? g hydrate 2. What is the mass of the anhydrous CoSO,? g CoSO, 3. How much water was driven off? g H,O 61 I

List and describe three characteristics of a good recrystillzation solvent

What precautions are applicable to this lab? Select ALL that apply. Always wear your safety goggles in the lab. Dispose of any used melting point tubes in the broken glass container. 18 M sulfuric acid is corrosive. Notify your instructor of any spills, and rinse skin immediately upon contact. Take care when using the Mel-Temp apparati as areas will become hot.

What characteristics made PCBs so useful for industry and what were they primarily used for?

Which refluxing apparatus is set up to keep moisture out? A O C O B and C O A OB Onone B с

1. What is the purpose of the boiling chips?

Watchglass Bent glass hook Arrangement for the drying of samples. It shows the recommended way to dry a sample. The weighing bottle is contained in a labeled beaker with a ribbed cover glass. Weighing bottle with cap ajar Beaker Reagent True O False

Briefly describe how you should protect your hands while you are inserting glass tubing into a stopper.