Question

In: Chemistry

Predict the effect on each of the following if the product was not completely dried after...

Predict the effect on each of the following if the product was not completely dried after the recrystallization:
(a) percent yield; (b) melting point; (c) IR spectrum.

Solutions

Expert Solution

Solution

a) Percent yield.

If the product is not well dried and if its mass is recorded as the experimental yield then the moisture present in the moistened solid will lead to increase in the mass of the product which would be higher than its actual mass and it will given higher mass of the product obtained than its actual mass. Therefore the percent yield will be higher.

b) Melting point

If the product is not dried and contains the moisture then the melting point determinations would not be correct because the moistened substance will not filled well in the capillary tube to record the melting point which will not give the correct readings for the temperature of the melting point. Also the solvent present in the product affect the melting point because the melting point and boiling points of the impure compounds are different than the pure compounds. So we may get higher or lower melting point depends on the solvent present in the product.

c) IR spectrum

If the product is not well dried and contains the solvent portion in it then this solvent portion is nothing but the impurity present in the product. Therefore this solvent portion will give the unnecessary IR spectrum peaks in the IR spectrum of the product which would give the incorrect IR spectrum peaks for the product and this will make difficult to exactly figure out the functional groups present in the product. The IR peak intensity and the number of peak will be depend on the nature (type) of the solvent used. Therefore to avoid these errors the product must be well dried.


Related Solutions

Define and completely describe the effect that each of the following have on the audit of...
Define and completely describe the effect that each of the following have on the audit of inventory -- FOB -- Consignment
4. Under each of the following conditions, please predict the effect the mutation will have on...
4. Under each of the following conditions, please predict the effect the mutation will have on the rate at which glycolysis will proceed in liver cells: a. Loss of the allosteric site for ATP in phosphofructokinase b. Loss of binding site for citrate in phosphofructokinase c. Loss of the phosphatase domain of the bifunctional enzyme that controls the level of fructose 2,6-bisphosphate d. Loss of the binding site for fructose 1,6-bisphosphate in pyruvate kinase.
Predict the effect of the scenarios below on expression levels of each of these gene classes...
Predict the effect of the scenarios below on expression levels of each of these gene classes in the embryo described (will expression increase, decrease, or be unaffected) and explain the reason for your prediction.   A) A fly embryo has a mutation that causes increased expression of the knirps gene (gap genes).   B) A fly embryo has a mutation that blocks expression of the nanos gene (maternal genes). C) A fly embryo has a mutation that decreases expression of the runt...
Predict what effect each of these venoms would have had on the muscle contractions of the...
Predict what effect each of these venoms would have had on the muscle contractions of the biventer cervicis muscle. Remember to justify your answer Venoms and Reactions - 1.      Redback spider (Latrodectus hasseltii) – contains a toxin which forms pores in the cell membrane of neurons, allowing the influx of Ca2+ into the nerve terminal 2.      Blue-ringed octopus (Hapalochlaena lunulata) – contains a toxin which blocks voltage-gated Na+ channels 3.      Funnel-web spider (Atrax robustus) - contains a toxin which causes delayed inactivation of...
Predict the effect of a bottleneck or founder effect on allelic diversity.
Predict the effect of a bottleneck or founder effect on allelic diversity.
What effect will each of the following have on the demand for product B? Indicate how...
What effect will each of the following have on the demand for product B? Indicate how the demand side will change for each one. a) Product B becomes more fashionable. b) The price of substitute product C falls. c) Income declines and product B is an inferior good. d) Consumers anticipate that the price of B will be lower in the near future. e) The price of complementary product D falls.
Predict and explain the effect on the option’s premium from the following: for a call option,...
Predict and explain the effect on the option’s premium from the following: for a call option, a reduction in variance of the underlying security;   for a put option, a reduction in variance of the underlying security;       for a call option, a lower exercise price;    for a put option, a lower exercise price.
For each of the following processes, use a calculation to predict whether or not it will...
For each of the following processes, use a calculation to predict whether or not it will occur spontaneously. (For some cases you may need to use data from Appendix A in your textbook.) a) A piston with radius of 15.6 cm containing 2.86 L of an ideal gas (Cv,m = 3/2 R) at 1.00 atm, 298.15 K undergoes isothermal compression by the addition of a 5.64 kg weight. b) The combustion reaction for methanol CH4O(l) at 298.15 K carried out...
The following reaction has achieved equilibrium. Predict the effect on the formation of phosphorous pentachloride (increase,...
The following reaction has achieved equilibrium. Predict the effect on the formation of phosphorous pentachloride (increase, decrease or no effect) for the stated changes to the system: PCl5(g)←→PCl3(g)_Cl2(g) A) The concentration of phosphorous trichloride is increased. B) The concentration of chlorine is increased. C) The volume of the container in which the reaction is taking place is suddenly made smaller. D) The pressure of the system is increased by adding one atmosphere of gaseous nitrogen to the container. Could you...
For each of the following reactions predict the products, converting each to a balanced formula equation....
For each of the following reactions predict the products, converting each to a balanced formula equation. Include physical states in your answer. a.(a) Aqueous solutions of copper(II) sulfate and potassium hydroxide are mixed together. (The solution turns cloudy and light blue during the reaction.) (b) Aqueous solutions of phosphoric acid and sodium hydroxide are mixed together. (Heat is produced during the reaction.) (c) Solid sodium bicarbonate is mixed with phosphoric acid. (Bubbles of gas are formed during the reaction.) (d)...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT