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* A student cools a sample in a capillary tube after melting it. Upon attempting to determine the melting point on...
Post lab questions for chromatography and melting point lab. i have a few ideas of what the answers to these questions s...
Post lab questions for chromatography and melting point lab. i
have a few ideas of what the answers to these questions should be,
but I would like to double check. if anyone can help me, that would
be so awesome. Thank you!
A student cools a sample in a capillary tube after melting it. Upon attempting to determine the melting point on the same sample, the student does not obtain the same melting point. Why? A student places his TLC...
A student performs two melting-point determinations on a crystalline product. In one determination, the capillary tube...
A student performs two melting-point determinations on a crystalline product. In one determination, the capillary tube contains a sample about 1−2 mm in height and the melting range is found to be 141−142°C. In the other determination, the sample height is 4−5 mm and the melting range is found to be 141−145°C. Explain the broader melting-point range observed for the second sample. The reported melting point for the compound is 143°C. Explain what may have caused the broader melting range...
3. If the TLC plate development had stopped before the solvent front reached the top of...
3. If the TLC plate development had stopped before the solvent front reached the top of the TLC plate (i.e. maybe it reached the middle of the TLC plate when it was stopped, instead): a) Would the Rf values have been affected? If so, how? If not, why not? Give a numerical example to support your answer. b) Would the size of the spots have been affected? If so, how? If not, why not? (Hint: think about the diffusion of...
please do two pargraph about this pre lab and lab include Title,purpose ,chemical eqution if their...
please do two pargraph about this pre lab and lab include
Title,purpose ,chemical eqution if their any ،Procedure
,Hazards(hazard Identification,physical and chemical
properties),Experimental Phase, Data
&Observations,Data&Observations cont (melting point and
meling point). and Calcuations
Spinach Laboratory Procedure PROCEDURES Isolation of pigment from leaves: 1. Wash the spinach leaves. Weigh 1.0 g-2.0 g of dry spinach leaves. Remove any stems and veins from the leaves before you weigh. 2. Combine 1.0 g of anhydrous magnesium sulfate with 0.5 g of sand...
Provide a brief rationale for why ( Please help me answer all questions please this is SO important) When benzoic acid is mixed with inorganic sand, what happens to the melting point of the sa...
Provide a brief rationale for why
( Please help me answer all questions please this is SO
important)
When benzoic acid is mixed with inorganic sand, what happens to the melting point of the sample? 6. a. It increases b. It decreases c. It stays the same. d. It increases above the actual melting point then decreases. e. It goes below the eutectic point 7. In thin-layer chromatography, the observed Rr will change upon changing any of the following parameters...
30pts total) 1. Irwo known substances have the same melting point as an unknown substance that...
30pts total) 1. Irwo known substances have the same melting point as an unknown substance that you obtained, how could you determine if either of the two known substances is your unknown compound? 2. You are given an impure mix of substances that contains a solid substance, Chemical X, that is soluble in ethanol at all temperatures. You know there is an insoluble impurity in the mix as well as a very soluble impurity, both in ethanol. Can you recrystallize...
Question 5 (0.5 points) A certain compound is spotted on the starting line of a small paper chromatogram and that same compound is spotted again on a much larger paper chromatogram. Both papers...
Question 5 (0.5 points) A certain compound is spotted on the starting line of a small paper chromatogram and that same compound is spotted again on a much larger paper chromatogram. Both papers are developed using the same solvent and are pulled out when the solvent is 2 cm from the top. Which statement is true regarding the R of the spot after development? C) The spot on the larger paper should have a higher Rf because the spot travels...
1. Why do soluble impurities affect the melting point while insoluble impurities are expected not to...
1. Why do soluble impurities affect the melting point while insoluble impurities are expected not to affect the melting point? (3 points) 2. Why cold solvents are preferred during recrystallization and when is recrystallization selected vs other purification techniques you have learned during 3210 labs. (3 points) 3. The solid compound "X" has two components (A and B). After heating the solid powder (X), one component (A) is left and the other component (B) evaporated directly. Comment on the nature...
BOILING POINT 1. Why is it necessary to position the sample tube right next to the thermometer bulb in the Thiele tube? 2. The normal boiling point of benzene is 80 degrees C. What is the vapor pressu...
BOILING POINT 1. Why is it necessary to position the sample tube right next to the thermometer bulb in the Thiele tube? 2. The normal boiling point of benzene is 80 degrees C. What is the vapor pressure of benzene at 80 degrees C? 3. Define boiling point. How does this definition describe what is occurring in micro-boiling point determination method i.e. that the boiling point is the temperature at which the liquid levels inside and outside of the capillary...
QUESTIONS TO ANSWER: Prepare a table of all chemicals used with the structure and purpose of...
QUESTIONS TO ANSWER:
Prepare a table of all chemicals used with the structure and
purpose of each.
Calculate the theoretical yield by finding limiting reactant of
the experiment by converting reactants to product (remember to show
all calculations used)
Calculate the percent yield using the limiting reactant
Calculate the Rf for triphenylmethanol. If there are two dots,
determine which one is triphenylmethanol.. ( I did not provide
data. Please let me know how I Would do this if I did)...
Post lab questions for chromatography and melting point lab. i
have a few ideas of what the answers to these questions should be,
but I would like to double check. if anyone can help me, that would
be so awesome. Thank you!
A student cools a sample in a capillary tube after melting it. Upon attempting to determine the melting point on the same sample, the student does not obtain the same melting point. Why? A student places his TLC...
please do two pargraph about this pre lab and lab include
Title,purpose ,chemical eqution if their any ،Procedure
,Hazards(hazard Identification,physical and chemical
properties),Experimental Phase, Data
&Observations,Data&Observations cont (melting point and
meling point). and Calcuations
Spinach Laboratory Procedure PROCEDURES Isolation of pigment from leaves: 1. Wash the spinach leaves. Weigh 1.0 g-2.0 g of dry spinach leaves. Remove any stems and veins from the leaves before you weigh. 2. Combine 1.0 g of anhydrous magnesium sulfate with 0.5 g of sand...
Provide a brief rationale for why
( Please help me answer all questions please this is SO
important)
When benzoic acid is mixed with inorganic sand, what happens to the melting point of the sample? 6. a. It increases b. It decreases c. It stays the same. d. It increases above the actual melting point then decreases. e. It goes below the eutectic point 7. In thin-layer chromatography, the observed Rr will change upon changing any of the following parameters...
30pts total) 1. Irwo known substances have the same melting point as an unknown substance that you obtained, how could you determine if either of the two known substances is your unknown compound? 2. You are given an impure mix of substances that contains a solid substance, Chemical X, that is soluble in ethanol at all temperatures. You know there is an insoluble impurity in the mix as well as a very soluble impurity, both in ethanol. Can you recrystallize...
Question 5 (0.5 points) A certain compound is spotted on the starting line of a small paper chromatogram and that same compound is spotted again on a much larger paper chromatogram. Both papers are developed using the same solvent and are pulled out when the solvent is 2 cm from the top. Which statement is true regarding the R of the spot after development? C) The spot on the larger paper should have a higher Rf because the spot travels...
1. Why do soluble impurities affect the melting point while insoluble impurities are expected not to affect the melting point? (3 points) 2. Why cold solvents are preferred during recrystallization and when is recrystallization selected vs other purification techniques you have learned during 3210 labs. (3 points) 3. The solid compound "X" has two components (A and B). After heating the solid powder (X), one component (A) is left and the other component (B) evaporated directly. Comment on the nature...
QUESTIONS TO ANSWER:
Prepare a table of all chemicals used with the structure and
purpose of each.
Calculate the theoretical yield by finding limiting reactant of
the experiment by converting reactants to product (remember to show
all calculations used)
Calculate the percent yield using the limiting reactant
Calculate the Rf for triphenylmethanol. If there are two dots,
determine which one is triphenylmethanol.. ( I did not provide
data. Please let me know how I Would do this if I did)...
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