Answer:Acid catalyst is needed to increase the electrophilicity of Carbonyl group of Carboxylic acid as alcohol is a weak nucleophile.
Alternatively esters can be synthesised by converting carboxylic acid into acyl chloride using thionyl chloride(SOCl_{2} and then further treating acyl chloride with alcohol.
Carboxylic acid and esters can be easily distinguished on the basis of IR as carboxylic acid would contain a broad intense peak in 2500-3200cm_{-1} corresponding to OH stretching frequency whereas esters would not contain any such broad intense peak.
Alcohol and esters can also be distinguished using IR as alcohols would contain a broad intense peak at around 3200-3600cm_{-1}
Explanation: For the synthesis of esters using alcohol and carboxylic acid we need to add a little amount of acid in the reaction . The acid used here increases the electrophilicity of carbonyl carbon and hence makes it easier for a weaker nucleophile like alcohol to attack the carbonyl carbon of acid.
The oxygen of the carbonyl group is protonated using the acidic proton which leads to the generation of positive charge on the oxygen. The positive charge generated is delocalised over the whole acid molecule and hence the electrophilicity of carbonyl group is increased. Kindly refer attachment for the structures.
If we simply mix the acid and alcohol then no appreciable reaction would take place between them and ester formation would not take place because the carboxylic acid in that case is not a good electrophile whereas alcohol is also not a very strong nucleophile which can attack the carbonyl group.
Alternatively we can use thionyl chloride or any other reagent which can convert the carboxylic acid into acyl chloride. Acyl chloride is very elctrophilic and alcohol can very easily attack the acyl chloride and esters could be synthesized.
The carboxylic acid and ester can very easily be distinguished on the basis of broad intense OH stretching frequency peak at around 2500-3200cm_{-1} . The broad intense OH stretching frequency peak is present in carboxylic acids as they contain OH groups and absent in case of esters .
Likewise esters and alcohols can also be distinguished on the basis IR spectra as alcohols will have broad intense spectra at around 3200-3600cm_{-1}corresponding to OH stretching frequency whereas esters will not have any such peak. Rather esters would be having a Carbonyl stretching frequency at around 1720-1760
Hey there!:
The hydroxyl groups act to neutralize the sodium borohydride which reduces yield.
Hope that helps!
Answer:
Depth and location affect ocean water’s temperature.
Explanation:
The main source of heat for the oceans is solar radiation. That is, water is basically heated by the radiation of the Sun, which transmits energy to the surface. The ocean absorbs this energy and stores it. Seawater has high caloric capacity. This means that more energy and more time is needed to change or increase the water temperature, compared to the air temperature. Similarly, once the ocean heats up, it takes a long time for the water to completely release or lose that heat.
The temperature decreases to greater depth, because the amount of solar radiation is reduced. On the contrary, it is greater where there is greater energy or heat content.
The closer a place is to the equator, the solar energy will affect more vertically and with more intensity on it, so the warmer the temperatures will be. The further that point of the equator is found, the solar energy will reach it with a smaller angle. And if the point is near the poles, the sun's rays will arrive at a very small angle. This causes the temperature of the water of the oceans to vary depending on the earth's latitude, being higher in areas close to the equator and the tropics, and colder the closer to the poles or the further away from the temperate zones.
Answer:
it's got to do something with milk I guess it's the sugary substance found in milk and it's a compound