In crude cyclohexene, what is the purpose of adding refined salt to saturate the water layer

Salting out is performed to reduce cyclohexanol.

Solubility in water.

Facilitates the removal of cyclohexanol.

Saturated saline has a deemulsifying function in the separating funnel.

Stratification is more pronounced in the mixture. The solubility of cyclohexene in saturated salt water is small, whereas the solubility of cyclohexanol in it is large. This can wash away the unreacted cyclohexanol and prevent the loss of cyclohexene dissolved in it.

Chemical propertiesAn addition reaction can occur.

It is flammable, and its vapor and air can form a ** mixture, which is very flammable in case of open flame and high heat. It can react strongly with the oxidant to cause combustion or **. Long-term storage can produce potentially hazardous peroxides.

Its vapor is heavier than air, can spread to a considerable distance at a low place, and will catch fire and ignite when exposed to an ignition source.

The above content reference: Encyclopedia-cyclohexene.

Salting out further reduces the solubility of cyclohexene in water for separation.

Another effect is that because the density of cyclohexene is greater than that of water, after adding salt water, the dissolved density becomes larger, so that it exists on the top of the dissolution and is convenient for separation.

Prevent cycloethylene from dissolving in water?

Saturated brine has the function of deemulsification, and the stratification of the mixture in the separating funnel is more obvious, and it can produce salting out effect.

According to the query question bank, what is the purpose of adding salt to saturate the water layer in crude cyclohexene? The answer is that saturated food teaser brine has the function of deemulsification, and the mixture stratification in the separating funnel is more obvious, and it can produce salting out effect, so that the solubility of cyclohexene in water is further reduced and easy to separate, and there is also a role that because the density of cyclohexene is greater than that of water, after adding salt mountain grinding water, the dissolved density becomes smaller, so that it can reduce the solubility of organic matter in water.

This question paper is from the 2016 high school entrance examination chemistry model test questions in Wuxi City, Jiangsu Province, including analysis.

(1) According to the knowledge of ethylene making experiment, the function of the broken porcelain piece in the generating device A is to prevent overboiling, because the boiling point of the generated cyclohexene is 83, to obtain liquid cyclohexene, condensation effect of condensation in addition to gas conduction, which is convenient for cyclohexene condensation, so the answer is: to prevent overboiling; Condensation; The purpose of the ice water bath is to reduce the temperature of cyclohexene vapor and liquefy it, so the answer is: further cooling to prevent cyclohexene from volatilizing (2) Cyclohexene is a hydrocarbon, insoluble in sodium chloride solution, and the density is smaller than that of water

Ethyl acetate is prepared.

When purifying the product, the acid can be removed by washing with C (Na2CO3 solution); So the answer is: upper; c；In order to increase the condensation effect, the distillation device should have a condenser tube to cool the water.

Entering from the lower mouth (g), the cooling water and the gas form a counterflow, and the condensation effect is better; It is easier to fill the condenser tube with water; In order to prevent the condenser tube from bursting due to sudden cooling and heating at the steam inlet, the answer is: g; The cooling water and gas form a counterflow, and the condensation effect is better; It is easier to fill the condenser tube with water; In order to prevent the condenser pipe from rupturing due to sudden cooling and heating at the steam inlet; According to the data in the table, the boiling point of the fraction cyclohexene is 83, so the temperature of the collected product should be controlled at about 83. a. When distilling, the product is collected from 70, collected in advance, the product is mixed with impurities, and the actual output is higher than the theoretical output, so A is wrong; b. The actual dosage of cyclohexanol is too much, and the amount of cyclohexene substance produced.

Increasing, the quality of the experimental cyclohexene is higher than the theoretical yield, so B is wrong; c. If cyclohexanol is mixed in the crude product, the amount of cyclohexanol consumed by the determination increases, and the quality of the prepared cyclohexene boutique is lower than the theoretical yield, so C is correct; , so choose c; So the answer is: 83 ; c；(3) To distinguish between crude and fine products, you can add metal sodium to observe whether there is gas generated, if there is no gas, it is a fine product, and there is no fixed boiling point according to the mixture, and the pure substance.

There is a fixed boiling point, and the purity of the product can also be judged by measuring the boiling point of crude cyclohexene and cyclohexene boutique, so the answer is: BC

saturated, water may be easily removed.