You have synthesized a substance from aqueous solution that has a melting point of 152 °C. A pure authentic sample of the intended product has a melting point of 154 °C. The most likely explanation for the difference in melting

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Chemistry

You have synthesized a substance from aqueous solution that has a melting point of 152 °C. A pure authentic sample of the intended product has a melting point of 154 °C. The most likely explanation for the difference in melting temperature is that the your product is impure...

chemistry

Urgent. The melting point of pure acetylsalicylic acid is 135 degrees celsius. Comment on the purity of your product based on its melting point range. My melting point range was 105-115. I do not even know where to start for this question. Could you please help?

chemistry

Say you have two substances, A and B. A has a melting point of 300 degrees Celcius, while B has a melting point of 200 degrees Celcius. If you took a mixed melting point where the ratio of A is higher than B, what would the melting range look like? Would the melting point be ...

Chemistry

student perform 2 melting point determinations on a crystalline product. In one determination, the tube contained a sample 1 - 2 mm in height, and the melting point was 141 - 142 ¢ªC. In the second determination, the sample hight was 4 - 5 mm and the melting range was 141 - ...

ORG CHEM LAB

Im doing a conclusion on a lab of acetaminophen. We were to take a melting point of the crude smale of acetaminophen and melting point of the crystallized acetaminophen. The mp for crude sample: 169.2 degree C The mp for crystallized sample: 172. degree C Why the change in mp'...

chem

1.) When determining the melting point it's described in my text as recording 2 points in the melting process. a) when the first drop of liquid is seen b) when all of the compound is liquified and since I have to determine the melting point of sulfanilamide pure and impure (I ...

chemistry

Pure acetylsalicylic acid has a melting point of 135.0 - 135.5 (degrees Celsius). What would you expect for the melting point is this was mixed as a 50:50 mixture with pure benzoic acid (melting point 121 - 122)? Explain.

Melting point

Could you tell me what the melting point for a crystallized sulfanamide is? Also, we will have to determine the m.p. of an impure sulfanamide. Any idea of a temperature range for that? Will it be higher of lower? Probably hard to tell since I don't know what the impurity will ...

Chemistry

Sample A: Solid appearance:crystals, solids, white Solid Conductivity:no Solubility: soluble Solution appearance:substance disappears slowly Solution Conductivity: yes Relative melting point:2nd Sample B: Solid appearance:brown, tiny solids, dirt appearance Solid Conductivity...

orgo

A sample of naphthalene, which should be pure white, was found to have a grayish color after the usual purification procedure. The melting point was correct, and the melting point range was small. Explain the gray color.

Organic Chemistry

Why is the melting point of a known compound (ex. acetanilide) determined before the melting point of the unknown compound? I think it is to determine if the unknown is a pure substance but I am not sure..I just need to be pointed in the right direction.

ochem

You have a mixture composed of 90% benzoic acid and 10% naphthalene. Benzoic acid has a melting point of 122.4 oC, while naphthalene has a melting point of 80.2 oC. You can say with certainty that the melting point of the mixture will be: A. greater than any of the two melting...

organic chem/ melting pt lab

why does a soluble impurity reduce the melting point range of a pure compound ? why is it advisable to run a mixed melting point determination on samples of two different compositions before concluding that the two compounds are identical ?

CHEMISTRY

which of the following elements would have the highest melting point?> a)K b)Mg C)Na D)al e)Ca Calcium would have the highest, follwed by aluminum, magnesium, sodium, lowest melting point-potassium. Please double check thank you i found that you are correct with the melting...

Chemistry

Posted by ann on Sunday, October 17, 2010 at 4:26am. In melting point determination, why shouldn't a substance be re-melted? (i.e. why should we not re-melt a substance that has previously been melted in a melting point tube?)

Chemistry

In melting point determination, why shouldn't a substance be re-melted? (i.e. why should we not re-melt a substance that has previously been melted in a melting point tube?)

Chemistry

A sample of naphthalene, which should be pure white, was found to have a grayish color after the purification procedure. The melting point was correct but the melting point range was smaller. Why the gray color? Is it possible the "purification procedure" included charcoal? ...

organic chemistry

A sample of Compound X is analyzed and found to have a melting point range of 110-120 °C. Would you try to purify it further to get a sharper melting point? Why or why not?

Organic Chemistry!!!

pure acetylsalicylic acid has a melting point of 135.0 - 135.5 degreed celsius. what would you expect to happen to the melting point if this was mized as a 50:50 mixture with pure benzoic acid (mp 121 - 122)

Chemistry

Imagine that you have a pure sample of an unknown compound that you are told is either 2-naphthol OR benzoic acid. In the lab, you also have access to samples of pure 2- naphthol and pure benzoic acid. However, both of these pure substances melt at 123 °C: the same ...

Organic Chemistry - Melting Point

You have an unknown with an observed melting point of 90-93°C. Is your unknown compound A with a reported melting point of 95.5-96°C or compound B with a reported melting point of 90.5-91°C? Explain.

chemistry

intermolecular forces Rank the following substance from highest melting point to lowest melting point. My teacher gave a list of compounds: H2O, NO2,F2,CI2 and to have a high melting point means that you need a stronger IMF. Rank the following substances from highest freezing ...

chemistry

this is what my lab report looks like (minus the graph of the first part) im stuck on part II I. A. unknown 1 melting point range (uncorr) 50.0-53.0 melting point range (corr) 50.2-53.2 (because of graph from part 1 of experiment) melting point average 51.7 b unknown 2 melting...

physics

Entropy of melting A block of a certain substance (m = 0.3 kg) sits in a cold room at its melting point 170 K. A lab demonstrator supplies heat at a rate of 200 W for 140 seconds by focusing light on the block to (just) completely melt the block. (a) What is the latent heat of...

chem

A student in 51LA conducts a melting point experiment with an unknown compound and observes a melting range of 122 – 129 °C. Is this a typical range for a melting point? If not, what range would be typical? Well for a pure compund the meliting range is from .5 to 2.0C. I ...

Same substances?

Question: Two substances, A and B, have the same melting point. how can you determine if they are the same without using any form of spectroscopy? Explain in detail. My answer: Perform a mixture melting point. In this procedure, pulverize and mix A and B in equal quantities.. ...

chem

1.Which of the following elements has the largest known oxidation number (in magnitude)? Pt Au Os Fe Ru 2.Which of the following metals has the highest melting point? Al Mg K Na Ca I know that Ca is wrong because I tried it, so I really think it has to be Na that has the ...

Chemistry

The melting point of a pure solvent (kf=1.79°C/m) is -116.3°C. If 312 g of an ionic solid (i=2.6) is added to 567.7 g of the solvent, the new melting point is -101.6°C. What is the molar mass of the ionic solute?

Organic chemistry

An unknown compound (x) melts at 60°C and is mixed with a compound (y) that melts at 45°C and is soluble in x. Will the Melting point for the mixture start below 45°? I think so, because if you look at ice and salt for an example, salt has a way higher melting point than ...

Chemistry

If we wish to find the molar mass of a pure solid organic compound, which measurement would be most useful and why? A)melting point of the solid B)melting point depression of the mixture of the solid with 1,4-dichlorobenzene C)Heat of combustion D)solubility in water

Chemistry

A student who was isolating aspirin stopped the experiment after filtration step alumina. One week later, the methanol was evaporated and the experiment was completed. The melting point of the aspirin was found to be 110-115 degrees C. Explain why the melting point was low and...

Mixed melting point

Question: A compound melting at 134 degrees C was suspected to be either aspirin (mp 135C) or urea (mp 133C) Explain how you could determine whether one of these two suspected compounds was identical to the unknown compound without using any form of spectroscopy. This seems ...

Organic chemistry

If the aspirin crystals were not completely dried before the melting point was determined, what effect would this have on the observed melting point ?

Chemistry

Of each pair of solids, which one has the higher melting point? a) HCl and KCl b) Cu and Kr. Can you please explain? How do you know the melting point? Is it the type of intermolecular force that they have? thanks!

chemistry

why does BeCl2 have low melting point but SiO4 has high melting point even though they are both covalent bonds between the atoms

org. chem.

A student who was isolating aspirin stopped the experiment after the filtration step with alumina. One week later, the methanol was evaporated and the experiment was completed. The melting point of the aspirin was found to be 110-115 degress Celsius. Explain why the melting ...

Chemistry

Student in O-Chem Lab conducts a melting point experiment with an unknown compound and observes a melting range of 210 – 218C. Is this a typical range for a melting point? If not, what range would be typical? For this question, does it mean an unknown compound in general? I ...

Chemistry

What can be said about a substance with a triple point above 1atm 1) The liquid state of the substance cannot exist. 2) The gaseous state at 1 atm pressure cannot be condensed to the solid at the triple point temperature. 3) The melting point of the solid must be greater than ...

SCIENCE QUESTION

LEAD IS A SOFT, DENSE METAL WITH A SPECIFIC HEAT OF 0.028KCAL/KGC, A MELTING POINT OF 328.0C, AND A HEAT FUSION OF5.5KCAL/KG. HOW MUCH HEAT MUST BE PROVIDED TO MELT A 250.0KG SAMPLE OF LEAD WITH A TEMPERATURE OF 20.0C? Figure the heat to heat if from 20C to the melting point (...

Physical Science

Suppose an unknown substance has a melting temperature of 1,200 degrees Celsius and a density of 16.7 g/cm3. However, the different individual atoms that make up the substance have very different melting temperatures and densities. The unknown substance is most likely a ...

Portions and integers

I need help please. Mercury is a metal that is liquid at room temperature. Its melting point of -39 degrees Celsius. The melting point of isopropyl alcohol is -89 Celsius. (Part A) In the context of this problem, what does zero mean ? (I think it just tells if the liquid will ...

science

the melting point of pure benzoic acid and pure naphthol are 122.5 and 123 degree Celsius respectively. you are given a pure sample that is known to be either pure benzoic acid or 2- naphthol. describe a procedure you will use to determine the identity of the sample.

chemistry

Melting point experiment: how do i know the calibration curve? we did an experiment where: week one we did a graph with the melting points of different compounds. week 2 we used the graph to correct the melting point of unknown # 1 and then unknown # 2 we mixed unknown 2 with ...

science

how is melting point connected to science? how is melting point connected to math? how is melting point connected to the world? how is melting point connected to you? why is melting point important?

Chem

The melting point of KCl is 776 C whereas the melting point of NaCl is 801 C. 1. Identify the type of bonding in each substance. A: Both NaCl and KCl are ionic. 2. Account for the differences in the boiling points of the substances using principles of atomic structure, bonding...

physics

A substance has a melting point of 800ºC and a boiling point of 1465ºC. The substance is most likely A. water. B. hydrogen. C. gold. D. table salt. D?

Math

If neon has a melting point of -248 and hydrogen a melting point of -259. Is the melting point of neon greater or less than hydrogen's. I think greater than. Am I correct?

Chem

In the previous experiment, you recrystallized salicylic acid. If you were askedto take melting point of your crystals, would it be necessary to dry the salicylicacid crystals thoroughly first? What result would you expect from your melting point determination if you did not ...

Chemistry

Lead has a melting point of 327ºC, its specific heat is J/g•deg, and its molar enthalpy of fusion is 4.80 kJ/mol. How much heat, in kilojoules, will be required to heat a 500.0-g sample of lead from 23.0ºC to its melting point and then melt it?

Chemistry

Lead has a melting point of 327ºC, its specific heat is J/g•deg, and its molar enthalpy of fusion is 4.80 kJ/mol. How much heat, in kilojoules, will be required to heat a 500.0-g sample of lead from 23.0ºC to its melting point and then melt it?

Science (Chemisty)

The melting point of sodium is 97.8`C. Would you expect the melting point of iodine to be higher or lower?

chemistry

Describe how you would determine the melting point of a salt of benzoic acid with melting point of 170°c

Organic Chemistry

One sample that is 1mm in height has a melting point range of 200-201. What would be the melting point range of a 10mm sample in height if both samples heating rate is 2 degrees Celsius per minute? I'm thinking it would be about 2000-2010 but I'm not fully sure. I used algebra...

Chemistry

The melting point of aspirin : 128-137Celsius degree. The melting point of the crude aspirin was measured to be 128 Celsius degree. What does it indicate about the purity of the product?

chemistry

arrange these seven substances in order from highest melting point to lowest melting point. H2O, MgO, CCl4, CH2Cl2, CaCl2, N2, PF3

math/science

the melting point of the element bromine is about 19 grades F this is about 57 grades F more than the melting point of mercury. What is the melting point of mercury?

intermolecular forces

arrange these seven substances in order from highest melting point to lowest melting point. H2O, MgO, CCl4, CH2Cl2, CaCl2, N2, PF3

chemistry

1. Would it be advisable to determine the freezing point of pure p-dichlorobenzene with one thermometer and the freezing point of the solution with a different one? Explain. 2. If 0.150 mole of a nonvolatile non-electrolyte solute is present in 1200g of water, what are the ...

Chemistry

1. Would it be advisable to determine the freezing point of pure p-dichlorobenzene with one thermometer and the freezing point of the solution with a different one? Explain. 2. If 0.150 mole of a nonvolatile non-electrolyte solute is present in 1200g of water, what are the ...

brilient school

the melting point of mercury is -39 degree C .the freezing point of alcohol is -98 degree C .how much more is the melting point

chemistry

at one atmosphere pure water ice melts at 0.0 C. at 12 atm the melting point is -0.085 C. The density of water is 1g.cm^3 at 0 C, while that of ice is 0.917 g/cm^3. From this information, estimate entropy of melting.

chemistry

is melting point of 120-126 C a typical range for a melting point

Science

Study the data table below. A three-column table presenting the 'Melting Point and Boiling Point for Common Substances.' The column headers are 'Substance,' 'Melting point (°C),' and 'Boiling point (°C).' For substance aluminum, the values are '660' and '2519,' respectively...

Science

A substance has melting point of 0 Celius and a boiling point of 100 Celius. The substance is most likely * water * hydrogen * gold * table salt

physics

Suppose an unknown substance has a melting temperature of 1,200 degrees Celsius and a density of 16.7 g/cm3. However, the different individual atoms that make up the substance have very different melting temperatures and densities. The unknown substance is most likely a

Chemistry

Melting Point Determinations 1. Melting range of impure vanillin 2. Melting range of recrystalized vanillin 3. Melting range of 50% recrystallized vanillin + 50% phenyl carbonate

Sublimes?

Question: An unknown compound gave a melting point of 230C. When the molten liquid solidified, the melting point was redetermined and found to be 131C. Give a possible explanation for this discrepancy. My answer: The compound sublimed. How would sublimation work to do this? ...

LAB!!!!!

can someone check this for me???? Thanks I really appreciate it!!!!! Calcium Chloride Melting Point: 772 °C (anhydrous) Solubility (water): highly soluble in water Solubility (Ethanol): Soluble Conductivity: ATC mode: 183.25 Citric Acid Melting Point: 153 °C (426 K) ...

Chemistry

Why does MgO have a higher melting point than CaS? They are both ionic compounds with the same charges, but CaS is heavier so shouldn't it have a higher melting point?

Chemistry

Are the melting point and freezing point of a substance represented by the same number?

science

why can a scientist use boiling point or melting point to identify an unknow substance?

chemistry

you are conducting a freezing-point determination in the laboratory by using an aqueous solution of KNO3. The observed freezing point of the solution is -1.15 C. Using a pure water sample, you recorded the freezing point of the pure solvent of the same thermometer as .25 C. ...

Organic Chemistry

Melting Point Determinations between urea and trans-cinnamic acid. Q. If urea were a significant base, specifically how would your Melting Point Diagram be different?

Chemistry

Which of the following is NOT true? (A) CH2O Has a relatively high boiling point due to hydrogen bonding. (b) BaCl2 is an example of an ionic sold. (c) Ionic solids are poor conductors of heat and electicity. (d) The melting point of Fe is higher than glucose. (e) The melting ...

Chemistry

Substance A has a melting point of -10 degree celcius and a boiling point of 57 degree celcius. Sunstance B has a melting point of -67 degree celius and a boiling point of 15 degree celius. Room temperature is 20 degree celcius. (A) What is the physical state of substance A at...

Science

If the melting point of a substance is -39C, has the substance melted at 20C?

chemistry

a)Rank the following 3 tetrachloride compounds in terms of increasing boiling point: carbon tetrachloride (CCl4), methane (CH4), dichloromethane (CH2Cl2) b) Which molecule ( KI or LiF ) has the higher boiling point? c)Select the single most important reason below to justify ...

Statistics

The melting point of gold is known to be approximately 1,060 degrees centigrade. This is, of course, an average figure, for unavoidable ‘experimental error’ causes more or less variation from this figure whenever the test is actually performed. The best measure of these ...

physics

lead is a soft, dense metal with a specific heat of 0.028 kcal/kg degrees C, a melting point of 328.0 degrees C and a heat of fusion of 5.5 kcal/kg. How much heat must be provided to melt a 250.0 kg sample of lead with a temperature of 20.0 degrees Celsius? q1 = heat to move ...

science

In a serious accident, nuclear power plants reactor vessel cracks and all of the cooling water drains out. Although nuclear fission stops, radioactive decay continues to heat the reactor's 2.5× 10 to the 5 power kg uranium core at rate of 120 Mega-Watts. Once the core reaches...

Solid State Chemistry

Which molecule ( KI or LiF ) has the higher boiling point? Select the single most important reason below to justify your choice should have the higher melting point Both molecules are nonpolar but the higher melting includes hydrogen bonding Both molecules are nonpolar but the...

chemistry

2 solids samples each contain sulfer, oxyegen, and sodium only. These samples have the same color, melting point, density, and reaction with an aqueous barium solution. Are they solutions?

physical

Suppose an unknown substance has a melting temperature of 1,200 degrees Celsius and a density of 16.7 g/cm3. However, the different individual atoms that make up the element have very different melting temperatures and densities. Which is the unknown substance most likely?

physical

Suppose an unknown substance has a melting temperature of 1,200 degrees Celsius and a density of 16.7 g/cm3. However, the different individual atoms that make up the element have very different melting temperatures and densities. Which is the unknown substance most likely

chemistry

Which of the following statements about boiling points are true? A. The boiling point of 0.1 m NaF(aq) is lower than the boiling point of 0.1 m methanol(aq). B. The boiling point of a 0.5 m aqueous solution of LiOH is the same as the boiling point of a 0.5 m aqueous solution ...

Math

The table below shows the melting points of four elements. Which element has the highest melting point.

physical science

Suppose an unknown substance has a melting temperature of 1,200 degrees Celsius and a density of 16.7 g/cm3. However, the different individual atoms that make up the element have very different melting temperatures and densities. The unknown substance is most likely a

12th grade

Suppose an unknown substance has a melting temperature of 1,200 degrees Celsius and a density of 16.7 g/cm3. However, the different individual atoms that make up the element have very different melting temperatures and densities. The unknown substance is most likely a what?

Chemistry

you were asked to determine the melting point of an unknown compound in order to identify at as one of the compounds you had previously examined. What else could you have done to make sure that your unknown was indeed the compound you believed it to be, and not just a compound...

CHECK my answers Physical science

10. If a solid piece of iron is heated and remains at 80°C until it is completely melted, you know that 80°C is (2 pts) * a. the freezing point of iron b. the melting point of iron c. the boiling point of iron d. both the freezing and melting points of iron my answer would ...

chemistry

I did a lab about melting point. It is asking me for the purity of the compounds? How do I find it? Do I use melting points or percent yield?

science

Technician A and Technician B are examining the same substance. Technician A records the mass, volume, and weight of the substance and decides that it is sugar. Technician B records the melting point, density, and boiling point of the substance and decides that it is salt. ...

o.chem

I did an experiment for extraction of acetylsalicylic acid from an aspirin tablet(632mg mass). The solvent used was dichloromethane. I got about 342mg from the 500mg that could be extracted. the melting point found for this sample was 118-120°C as compared to a pure sample's ...

chem h/w

i did a lab and i need to find out the melting point for lauric acid and lauric acid with another substance. the teacher told us to figure it out using excel. this is my graph. tinypic. com/view.php?pic=1605yev&s=7 can someone help me in figuring out the two melting points?

chemistry

Determine the melting point of an aqueous solution containing 115 mg of saccharin (C7H5O3NS)added to 1.00 mL of water (density of water=1.00 g/mL, Kt=1.86 C/m)

math

Mercury is a metal, which is liquid at room temperature. Its melting point of alcohol is 39 Celsius the freezing point of alcohol is-114 Celsius. how much warmer is the melting point of mercury than the freezing point of alcohol?

Chemistry

For melting point determination, what is the optimum rate of heating near the melting point? What are the problems, if the rate of heating is too slow or fast?

science

1)effects of impurities on the boiling point of an organic compound. 2) purposes why melting points are determined. 3)suppose i am taking a melting point and the compound disappears, what must i do? Have you put any thought into these or do you expect us to do your homework? ...

math

metal mercury at room temperature is a liquid. melting point is 39 degree celsius.freezing point of alcohol is 114 degree celsius.how mu7ch warmer is the melting point of mercury than the freezing point of alcohol

chemisty

calculate the heat energy released when 25.8 g of liquid mercury at 25 C is converted to solid mercury at its melting point. Constants for mercury at 1 atm: heat capacity of Hg-->28.0 melting point-->234.32 K enthalpy of fusion-->2.29 kj/mol

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