Re: recrystallization Before packing into a capillary tube, a solid substance has to be powdered. Why is this done on a watch glass rather than on a piece of filter paper?
Q: Why would industry prefer to purify solids by sublimation or zone refining rather than…
A: The advantage of sublimation for purification process are i) Minimum amount of product is lost. ii)…
Q: What is the relationship between vapor pressure at a temperature and its melting point so that…
A: When a solid heated to give gas directly without leaving any residue is called sublimation this…
Q: What would a glassware assembly like this be used for? Heating a reaction under reflux conditions…
A: Fractional distillation is a process by which components in a chemical mixture are separated into…
Q: Using Dalton’s Law of Partial Pressure, explain how steam distillation is a useful technique for…
A: Dalton’s law of partial pressures is a gas law which states that the total pressure exerted by a…
Q: Consider why CaCl2 or MgCl2 are used as de-icers rather than NaCl is no longer used as a deicer.
A: De-icers or de-icing agents are substances that removes snow, ice from roads or any other surface.…
Q: For the liquid acetone, list all IMFs that have to be broken in order for it to mix with water
A: Solubility depends upon the polarity of the solvent. A polar solvent will be dissolved in the polar…
Q: Which of the following is a method that can help reduce the possibility of solvent bumping and…
A: In the given question we have to select the correct multiple option in which of the following method…
Q: What effect does the presence of impurity have on the melting point?
A: Melting point :- The temperature at which solid and liquid phases of a substance are in equilibrium…
Q: 1) During a melting point determination, the heating is constant and causes the temperature of the…
A: "Since you have asked multiple questions, we will solve the first question for you. If you want any…
Q: Why should solid diazonium salts never be separated from their mother liquor by filtration?
A: Why solid diazonium salts never be separated from their mother liquor by filtration - Let's discuss.
Q: Discuss how relative humidity in a cold storage room can influence the vapor pressure deficit.
A: Interpretation - To discuss how relative humidity in a cold storage room can influence the vapor…
Q: What is the purpose of placing the round bottom flask in a warm bath during rotary evaporation
A: Rotary evaporation is the process of reducing the volume of a solvent by distributing it as a thin…
Q: The presence of soluble impurities in a given substance A lowers the melting point of A because the…
A: The given statement is False as The presence of soluble impurities in a given substance A lowers the…
Q: i) What two criteria should you ensure about your melting point sample before you fill the melting…
A: Since you have posted multiple questions, but we will solve first question for you. For remaining…
Q: How much solid should be placed in a melting-point capillary tube?
A: The amount of solid that should be placed in a melting point capillary tube is given below.
Q: Why do banana and apple show discoloration when it left out in the open air for some time?
A: We know that banana and apple show discoloration when it left out in the open air for some time, or…
Q: Trans-oleic acid (18:1,D9) has a melting temperature of (44.5C) and cis-oleic acid (18:1,D9) has a…
A: Since we know that the melting point of any molecule is proportional to the effective packing of the…
Q: Describe the procedure you would follow in removing the lower and the upper layers from a separatory…
A: A question based on purification, which is to be accomplished.
Q: Explain the process of detergency using micelle formation.
A: A colloidal solution is a heterogeneous system in which one substance is dispersed as very fine…
Q: Explain why bimolecular condensation is a poor method for making unsymmetricalethers such as ethyl…
A:
Q: Heating of the oil bath must done slowly to get a more accurate reading of the melting point of a…
A: To observe the accurate melting point of a sample it is important to heat the sample slowly near the…
Q: Which part of sodium stearate, head or tail, is more likelyto be solvated by water?
A: The hydrocarbon part (tail) of sodium stearate is non polar and hydrophobic in nature. It repels…
Q: Explain what type of carbonate polymorphs may be present in saw dust derived biochar prepared at 300…
A: Saw dust is also known as wood shaving. It is by product obtained from biochar.
Q: describe the safety precautions you must take when removing the flask from the boiling-water bath
A: The safety precautions that one should take are:
Q: Why is the capillary tube placed such that the open end is above the oil level?
A: The capillary tubes are very thin in appearance. These are used to determine the melting point or…
Q: Briefly explain why it is important to use crucible tongs when you transfer the heated crucible (a)…
A: (a) It is very important to use crucible tongs when you transfer the heated crucible, why because…
Q: Enlist the uses of alcohol in extemporaneous compounding
A: We are to list uses of alcohol in extemporaneous compounding.
Q: Show in a detailed manner. 1. Draw and label the set-up for melting point determination using…
A: Answer - Capillary tube - Capillary tubing or capillary tubes are very thin tubes made of a rigid…
Q: In Purification by Sublimation, what improvement can suggest to increase the amount of crystals that…
A: Sublimation refers to when a substance in a solid-state and changes into vapours without going into…
Q: The generic structural formula for a 1-alkyl-3-methylimidazoliumcation is where R is a —CH2(CH2)nCH3…
A: As the length of alkyl group increases the structure becomes more and more non planar or…
Q: Describe the advantage and disadvantage of claudes process of gas liquefaction
A: Objective-describe advantages and disadvantages of Claude's process of gas liquefaction.
Q: A glass windowpane with a thin film of water on it reflects less than when it is perfectly dry. Why?
A: reflection is the change in direction of wave or light when it passes from one medium to another…
Q: Chromatography paper is fairly polar. How would you expect an ionic component to behave when the…
A: In a paper chromatography technique, as the solvent rises, the components adsorbed on the…
Q: When taking a melting point, only a very small sample size is needed to go into the capillary. Too…
A: Melting point is the temperature at which the solid substance changes to the liquid state upon…
Q: why should a small volume of the cold solvent be used for rinsing the pure crystal?…
A: Using a cold solvent, the impurities present in the surface of pure crystal is removed by rinsing…
Q: Always increases surface pressure (below the CMC) Results in micelles (above the CMC) Can be…
A: In colloidal and surface chemistry, the critical micelle concentration is defined as the…
Q: You are given an impure sample of fluorene. Your crystallization solvent choices are water, methyl…
A: Fluorene and toluene are quite non-polar, water is quite polar, and methyl alcohol is somewhere…
Q: In a recrystallisation, why are the newly formed crystals washed with cold solvent? -To wash off any…
A: Recrystallization is the technique that is used to purify solids. The basic principle is to dissolve…
Q: What are the different phase changes involved in the purification using sublimation experiment?
A: Sublimation is a process in which solid is directly change into gaseous without changing in liquid…
Q: In this lab, you used rotary evaporation to remove the neutral organic solvent. Rotary evaporation…
A: A rotary evaporator is a device used in chemical laboratories for the efficient and gentle removal…
Q: 4. Although we nearly always fire-polish the ends of cut glass tubing (to minimize the risk of…
A:
Q: A student placed about 1 cm of freshly recrystallized loosely packed solid into a melting-point…
A: The melting of the substance occurs over a range of temperatures. The melting of the substance may…
Q: Aside from London dispersion forces, which substance d interactions to be effective?
A: There are different types of forces act between the molecules:- Hydrogen bonding Dipole-dipole…
Q: How does the rate of temperature elevation influence the results of the melting point determination?
A: To find :The effect of rate of temperature elevation on melting point. Solution : As we know, the…
Q: What is the 3-dimensional drawing of this structure?
A: Note: Since you have posted question with multiple parts, we will solve only first three part for…
Q: Which liquid layer, top or bottom, do you expect to be the organic layer?
A: Which liquid layer, top or bottom, do you expect to be the organic layer?
Q: Explain the behavior of a cooled and remelted sample.
A: Given- A capillary shows a substantially higher melting point of 145°C. Repeated recrystallization…
Q: It is preferable to use the conical beaker for the crystallization process
A: Beakers (cylindrical) have a very wide surface area, which allows hot liquids to evaporate more…
Re: recrystallization
Before packing into a capillary tube, a solid substance has to be powdered. Why is this done on a watch glass rather than on a piece of filter paper?
Trending now
This is a popular solution!
Step by step
Solved in 2 steps with 1 images
- Filter paper is usually a poor material on which to powder a solid sample before introducing it into a capillary melting-point tube because small particles of paper may end up in the tube along with the sample. Why is this undesirable? and how might the presence of paper in the sample make the melting-point determination difficult1. Why does the solid need to be finely ground and then tightly packed in a melting point capillary tube?1. What is the limitation of the sublimation laboratory technique? 2. When can sublination be applied as a process of separation?
- What is the advantage of using Buchner filtration in filtering crystals? Q4. Briefly explain how scratching the wall of the glass flask can help formation of crystals.Why should solid diazonium salts never be separated from their mother liquor by filtration?Briefly describe the technique for packing a capillary melting point-tube
- What is the function of a desiccant in a set-up of volatilization gravimetry? To remove nitrogen from the sample To remove sulfuric acid from the sample To remove water vapor from the sample To remove carbon dioxide from the sampleHow does the rate of temperature elevation influence the results of the melting point determination?When performing a recrystallization of an impure solid, why is it important to allow the heated solution to cool slowly? Group of answer choices To encourage greater solid solubility. For the molecules of the solid being purified to arrange in organized crystal lattices. To avoid the need for using ice to cool the solution. To trap particles in the crystal lattice.
- Types of Co-Perciptation 1- Surface Adorption 2 - Mixed Crystal Formation 3- Occlusion 4- Mechanical Entrapment explain each type properly1. What limitations are encountered in the application of sublimation as a general method of purification? 2.Explain how a process of fractional sublimation might be applied to a mixture of two substances which sublime closely together.A student placed about 1 cm of freshly recrystallized loosely packed solid into a melting-point capillary tube. The student noted that the solid melted 30 degrees lower than expected and the solid seemed to jump/separate in the tube as the temperature increased in the melting point apparatus. When the student measured the melting point the following day with less solid that was more tightly packed, the melting point was at the literature value. Explain what all went wrong with the student's first sample
