Match the procedural step to its purpose. a. Flat-bottomed flasks transfer heat in an uneven fashion, and may fracture if heated strongly.
b. Methanol, which is used as a reagent and solvent, is flammable.
c. The unreacted carboxylic acid was neutralized under mild conditions.
d. Water needs to be removed before the liquid ester product is collected.

1. Magnesium sulfate is added to the dichloromethane layer before the solvent is distilled off.
2. The reagents were added to a round bottom flask prior to the reaction being heated under reflux.
3. The solution of benzoic acid and methanol was heated on a steam bath.
4. The reaction mix was washed with sodium carbonate solution.

Nanotechnology, the field of trying to build ultrasmall structures one atom at a time, has progressed in recent years. one potential application of nanotechnology is the construction of artificial cells. the simplest cells would probably mimic red blood cells, the body's oxygen transporters. for example, nanocontainers, perhaps constructed of carbon, could be pumped full of oxygen and injected into a person's bloodstream. if the person needed additional oxygen-due to a heart attack perhaps, or for the purpose of space travel-these containers could slowly release oxygen into the blood, allowing tissues that would otherwise die to remain alive. suppose that the nanocontainers were cubic and had an edge length of 24 nanometers. part a part complete what is the volume of one nanocontainer? (ignore the thickness of the nanocontainer's wall.) express your answer using two significant figures. v v = 1.4ă—10â’20 l previous answers correct significant figures feedback: your answer 1.3824â‹…10â’20 = 1.382ă—10â’20 l was either rounded differently or used a different number of significant figures than required for this part. if you need this result for any later calculation in this item, keep all the digits and round as the final step before submitting your answer. part b suppose that each nanocontainer could contain pure oxygen pressurized to a density of 81 g/l . how many grams of oxygen could be contained by each nanocontainer?

How do dying stars contribute to the formation of planets

Which one of the following bonds would you expect to be the most polar? a) b–h b) n–h c) p–h d) al–h e) c–h