The Organic Chem Lab Survival Manual: A Student's Guide to Techniques
10th Edition
ISBN: 9781118875780
Author: James W. Zubrick
Publisher: WILEY
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Question
Chapter 12, Problem 1E
Interpretation Introduction
Interpretation:
If someone has put about one-quarter of an inch of solid in the tube, should they go for an eye exam is to be explained.
Concept Introduction:
The melting point of a substance is the temperature at which it changes state from solid to liquid. This change occurs in atmospheric pressure and during melting point the two phases (solid and liquid) exist in equilibrium.
Nowadays in laboratory lots of equipment is available for determine the melting point of substance.
Put the correct amount of a solid in a melting-point tube.
Expert Solution & Answer
Answer to Problem 1E
The person should carefully put the correct amount of sample in the tube.
Yes the person should go for an eye exam, if someone has put about one-quarter of an inch of solid in the tube due to weak eyesight.
Explanation of Solution
A melting point is the temperature at which the first crystal just starts to melt until the temperature at which the last crystal just disappears. Take melting points only on dry, solid substances, never on liquids or solutions of solids in liquids or on wet or even damp solids.
Use only the smallest amount that you can see melt because larger samples will heat unevenly. The person should carefully put the correct amount of sample in the tube.
Yes the person should go for an eye exam, if he/she has put about one-quarter of an inch of solid in the tube due to weak eyesight.
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Students have asked these similar questions
Q1/Why do we use oil instead of water to determine the melting point of chemicals?
Q2/What is the reason for the variation in the measured melting point of the same chemical?
Q3/What is the best type of oil used to measure the melting point of chemicals? Why?
3. A student is trying to identify an unknown solid based on its melting point. She noted that the
compound began to melt at 172°C and finished melting at 177°C. Knowing it is possible for there
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Explain your reasoning.
4. A young chemist has synthesized what he believed to be acetaminophen. He measured the
melting point of this newly formed compound to be 163-178°C. If the literature value for the
melting point of acetaminophen = 169-170.5°C, would the young chemist be wise to consume
this product for headache relief? Why or why not?
2. Prepare an ice bath in a foam cup with ice and table salt. Place the cup in a beaker to give it more stability. The ice bath should be deep enough so that it is above the level of the water in the test tube but well below the top. Take care not to let any of the salt or ice get into the sample of distilled water.
* What is the predicted freezing point of water?
* Why do you think you need to put salt in the ice bath?
Chapter 12 Solutions
The Organic Chem Lab Survival Manual: A Student's Guide to Techniques
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