Concept explainers
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.
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.
Want to see more full solutions like this?
Chapter 12 Solutions
The Organic Chem Lab Survival Manual: A Student's Guide to Techniques
- Answer number 1-8. Number 4-8 is connected to each other.arrow_forwardFiltration of samples A, B, and C show no residue left. After letting them dry in different beakers, SAmple A remains no residues. Sample B shows crystal leftovers, and sample C show brown film on the beaker walls. This means that: a. Two or more samples are heterogenous b. Two or more samples are homogenous c. all sample have 2 or more phases d. all samples are purearrow_forward2. Explain how suction filtration is carried out in the laboratory. Give the important points that must be observed in doing the process.arrow_forward
- Pure aspirin has a melting point of 135-136 °C. Before the melting point was determined - if the sample contains water by absorbing moisture in the air - what effect could this have on the observed melting point from the sample?arrow_forwardA group of students performed a melting point experiment to study the physical properties of ionic and covalent solids. The data collected are shown in the table. Solid Sample Melting Point (oC) Time Elapsed (min) Table Sugar (sucrose) 186 18 Table Salt (sodium chloride) 500 (not observed) 30 Paraffin Wax 37 4 Vegetable Lard 50 >5 Using the information contained in the table, what is the BEST explanation for the results?A The melting point of sodium chloride was not observed because ionic solids do not melt, whereas sugar, wax, and lard melted because they are softer than salt.B The melting points of covalently bonded solids tend to be lower than ionic solids. The melting point of sucrose was greater than the wax or the lard because sucrose has stronger bonds than wax or lard.C The melting point of sodium chloride was not observed because ionic solids are composed of positive and negative ions that do not melt; whereas, the…arrow_forwardPAPER CROMATOGRAPHY • Define chromatography • Demonstrate an understanding of the process of chromatography • Describe the steps involved in a chromatography investigation Explanation Coloured inks are often made up of several different inks. Each colour of ink will get carried a different distance by the water, allowing you to see all of the different inks. Try this with different colours to see what actually goes into a colour. This technique is called chromatography and can be used in chemistry to find out what is in an unknown mixture. II. Materials .Felt tip pens (non-washable) . Kitchen roll .A bowl or cup . Water • Scissors III. Health and safety • Make sure that you thoroughly clean any equipment after the experiment before using for food IV. Procedure Method 1 1. Take a sheet of kitchen roll and draw a simple picture with a non-washable felt tip pen. 2. Place the sheet over an empty bowl. This is to keep the paper from getting too wet. 3. Carefully add a few drops of water…arrow_forward
- I need helping choosing all the right answers (Not honor class)arrow_forwardWhen a mixture of soluble liquids is heated all liquids are evaporated. The liquid with the _______________boiling point, however, forms the greatest percentage of vapor. A _________________column is needed to further separate the mixture. As the vapor moves up the fractionating column it becomes progressively ____________with the component that has the lowest boiling point. This is due to the vapor mixture continually condensing and _____________as it moves up the column. A thermometer is used to measure temperature of the gaseous fractions before they _____________The liquid with the lowest boiling point will be the first 'fraction' or portion of the _______________arrow_forwardExplain what would happen in a distillation if a student did not have cold water running through the condenser.arrow_forward
- Directions Through the given situations below, answer the following questions 1 A mixture of monosodium glutamate, white sugar, salt and benzoic acid is to be melted by a group of Grade 7 students to determine the behavior of the mother during melting Predict how the mixture will look like as it is being heated. Explain your answer SUBSTANCE Sali White sugar Monosodium glutamate Benzoic acid MELTING POINT 801 C 186 C 232 C 122 C 2. Theo wants to observe what will happen to substance X (melting point is at 78 C) after heating it on an evaporating dish. After heating for a few minutes, substance X startsarrow_forwardPlace a pinch of Sodium chloride on a teaspoon. Heat and note the time it takes to melt it. If after 3 minutes of heating, the substance does not melt, stop the heating and write your observations. (The first answer here is not clear)arrow_forwardWhat are the differences between a simple distillation and steam distillation?arrow_forward
- World of Chemistry, 3rd editionChemistryISBN:9781133109655Author:Steven S. Zumdahl, Susan L. Zumdahl, Donald J. DeCostePublisher:Brooks / Cole / Cengage LearningChemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage Learning
- Macroscale and Microscale Organic ExperimentsChemistryISBN:9781305577190Author:Kenneth L. Williamson, Katherine M. MastersPublisher:Brooks ColeChemistry: Matter and ChangeChemistryISBN:9780078746376Author:Dinah Zike, Laurel Dingrando, Nicholas Hainen, Cheryl WistromPublisher:Glencoe/McGraw-Hill School Pub Co