Melting Definition and 275 Threads

Okay, i am doing a lab involving crude acetaminophen and pure acetaminophen. The crude acetaminophen is supposed to have a lower melting point than the pure acetaminophen... how does that work and why? does it have to do with thermodynamics or what??

Homework Statement A sculptor has come to you with a problem, because she knows that you are such a good physics student. She wishes to make a lead casting of an object which will require 2 kg of melted lead. If the lead was stored in her basement at approximately 55˚F, and it is to be...

Homework Statement How much heat is needed to melt 16.7 kg of iron that is initially at 21.3°C? Homework Equations Q=m*c*ΔT + mL The Attempt at a Solution here: m=16.7kg, c=0.45kJ/kg*K, and ΔT=1538-21.3=1516.7 Thus, Q1=1.14e7 J Then, I need to calculate latent heat needed, which...

Homework Statement Hi, I need some help with a homework assignment I have, the scenario is as follows: The Saudi Arabian government has decicded to look into towing a large iceberg from Antarctica to solve problems with low water supply. As their top physics advisor, you are to explore the...

good day, this place is great, and i just got questions an AC electric arc furnace melts metal by way three electrodes and electric arcs generated by potential differences inside the furnace i had the opportunity to watch one in action and understanding the programming i see it controls...

A Carnot heat engine uses a hot reservoir consisting of a large amount of boiling water and a cold reservoir consisting of a large tub of ice and water. In 5 minutes of operation of the engine, the heat rejected by the engine melts a mass of ice equal to 3.40×10^−2 kg. Throughout this problem...

If you have a question such as "Which substance has the highest melting point?" & say these are the substances CH4, HF, He, CL2, how would you determine an answer? I'm not really looking for an answer to this particular question, but in general, there must be something I've forgotten in my...

Homework Statement the bob of an oscillating pendulum is made of ice.how is the time period affected if the bob starts melting? Homework Equations The Attempt at a Solution

Okay, if you have 1 kilomole of ice melting at 0 C and you have a given latent heat of fusion of ice as 3.348 x 10^5 J/kg and the density of ice as 917 kg/m^3 and te density of water as 999.9 kg/m^3, I don't understand how to find the work done. I know that work done is PdV, so it should be...

[SOLVED] Thermodynamics and ice melting. Homework Statement An open container holds ice of mass 0.585 kg at a temperature of -13.3 *C. The mass of the container can be ignored. Heat is supplied to the container at the constant rate of 800 J/min. The specific heat of ice to is 2100 J/Kgand...

1. What is the trend of melting points for primary alcohols? I can't understand why melting points dramatically change such as the increase is molecular weight. The melting points doesn't increase nor decrease but they increase and decrease differently when you increase the molecular weight...

Apparently, I heard CA glues were toxic while being warmed through hot glue guns. How long would an average human being survive if he were stuck in a closed room with his glue gun left one? I'm just wondering based on safety measures...since I heard CA held cyanide, I was wondering what the...

Aim: How does the volume of water at a given temperature affect the amount of ice that can melt in it? I did a lab experiment. I put ice in different volumes of water and waited for 5minutes. I measured the amount of ice melted and the final temperature of water. RESULT: (starting...

Homework Statement What is the effect of an insoluble impurity such as sodium sulfate, on the observed melting point of a impure compound? Homework Equations The Attempt at a Solution My answer is, there is no effect on the melting point of this particular compound. Because it...

if ice is heated to say 20C so it melts (done so slowly) is work done during the melting process equal to the latent heat? (I'm assuming there are no volume or pressure changes) just a small thing i can't recall or find a quick answer for right now.

Homework Statement I'm trying to calculate the power required to melt a 57.65g mass of ice, using what my professor calls a "thermoelectric heater and cooler consisting of many thermocouples" (I think its really called a Thermopile, but I havn't heard him use the term.) I took...

Homework Statement A Carnot heat engine uses a hot reservoir consisting of a large amount of boiling water and a cold reservoir consisting of a large tub of ice and water. In 5 minutes of operation of the engine, the heat rejected by the engine melts a mass of ice equal to 3.50×10−2 kg ...

Homework Statement A Carnot heat engine uses a hot reservoir consisting of a large amount of boiling water and a cold reservoir consisting of a large tub of ice and water. In 5 minutes of operation of the engine, the heat rejected by the engine melts a mass of ice equal to 3.30×10^-2 kg...

Melting Ice With Aluminum?? Homework Statement How many grams of aluminum at 90 degrees C would have to be dropped into a hole in a block of ice at 0.0 degrees C to melt 10 g of ice? Homework Equations Q = (m)(c)(deltaT) c of aluminum = 0.9 c of ice = 2.1 c of water = 4.186 333.7...

1. My professor gave us an extra credit problem in which we have to prove that water level does not change when ice melts. [b]2. (v)ice=(v)displaced water [b]3. any ideas?

URGENT HELP! Melting Iceberg: Latent heat of fusion Homework Statement Icebergs in the North Atlantic present hazards to shipping, causing the length of shipping routes to increase by about 30 percent during the iceberg season. Attempts to destroy icebergs include planting explosives...

200g of steel was placed on a big block of ice. The ice was 0 degrees C. The metal was 150 degrees C. How much ice gets melted? My attempt: Q=mc(changeinT) Q=.2(460)150 Q=13800 Q=ML 13800=M(3.34x10^5) M=.041317 kg is melted Is this correct?

entropy increases? entropy decreases ? no change in entropy? diffusion, evaporating, mixing, melting, separation i think diffusion - increase evaporation - increase mixing - increase melting - increase but what about separation :S? and if anyone thinks any others are...

Why do some elements, particularly the heavy ones, require melting for them to bond with other elements to create metals containing differing atoms? What role does temperature play in the form, conform, and inconform states of elements? And what role do the elements play in requiring...

Its 101F and 37% humidity. Stupid global warming.

if all the ice sticking out of the water from only the icebergs were to melt, would the water level go up or down?

I've heard that if the ice caps melt the oceans will rise. but i thought that water expands when freezing. is this a myth?

hi i am having a hard understanding melting points from my textbook. can someone please explain to me how they work and how you can determine melting points in the periodic table?

Which structure will have the highest melting point?

Hi everyone, I am new to this forum. I am taking an undergraduate thermodynamics course and got stumped by this problem. I found this forum and figured that someone here would be able to help me with this! :-p Homework Statement Develop a model for melting of an ice cube. What assumptions...

What happens to lead then you overheat it beyond its melting point, and what metal or chemical does it become then?

How to change the melting point of a metal? Like example: Iron melting point: 1535 °C Sulfur melting point: 115.36 °C If you combine Iron and Sulfur in a airtight container and light a monster fire under it, you get a sort of a pyrite (iron disulfide (FeS2)– Melting point 1,177-1,188 °C...

Homework Statement How many grams of aluminum at 90 C would have to be dropped into a hole in a block of ice at 0 C to melt 20 g of ice. Homework Equations Q = mcdelta T and Q = mLf c(H2O) = 1 cal/g.C c(Al) = 0.215 cal/g.C The Attempt at a Solution I can find the heat of fusion Q...

Homework Statement A 35 g ice cube at 0.0°C is added to 110 g of water in a 62 g iron cup. The cup and the water have an initial temperature of 36°C. Find the equilibrium temperature of the cup and its contents. Homework Equations heat lost by water+cup...

I have heard that when ice mixes completely with water then the Ice will be completely melted and the temperature of the water willl actually be below 0 C, is this true?

I have done some calculations so far but i am kind of stuck, here is the problem: A jar of tea is placed in sunlight until it reaches an equilibrium temp of 32.4 deg C. In an attempt to cool the liquid, which has a mass of 185g, 113g of ice at 0degC is added. Assume specific heat capacity of...

How would I show that the melting point of a solid decreases with increasing pressure knowing that the specific volume of the liquid is less than the solid? dP/dT=delta h / (T delta v) Clapeyron equation Inverse it: dT/dP = (T delta v)/delta h v" < v' : molar volume vapor < mol. volume...

I'm looking for a way to make paraffin wax have a higher melting temperature than it does, but without effecting how it drips. (this is for an artwork, so if it does then it spoils the look) Also without effecting the opacity too much. The melting temperature range I'm looking for is 100-110C...

I sincerely apologize for the broad and generic nature of my question, but I hope someone will be able to give me some guidance. I'm looking to learn more about the melting of ice, more specifically about the influence of a rise in temperature and the influence of light (most likely just...

Why Do Glasses Doesnt Have A Melting Point? And Are Glasses Liquid?thanks

http://www.utexas.edu/opa/news/2006/08/engineering10.html ''Science (DOI:10.1126/science.1129007)'' http://www.newscientist.com/data/images/ns/cms/dn9717/dn9717-1_464.jpg I like this one. Well, I like maps. I found it interesting in Northern Canada readings show +5.

Hello I was wondering: in which environment ice will be melt faster, air or water? I ahd argue with my friend recently, we needed Ice and he put it in pot with moderately cold water. Since we were outside and temperature was normal, about 17-18 Cel degree I said it will melt faster in water...

The temperature hit 102 at 12 o/clock, (taken at my front door) my new plants are wilting, and (they), think it will be the same tomorrow.

Hi. I was wondering if any of you could help me with how you would describe what goes on during melting and boiling? the answer would involve the use of molecular structures as well as the intermolecular forces that occurs between them. this is under the topic of thermal properties of matter...

Am I on the right track here? How much energy is required to melt 400 grams of lead, if the initial temperature is 25 oC? m=0.4kg deltaT 328-25= 303 SpecHeat = 128 Q=mCdeltaT Q=.4*128*303 15513.6J

hello there about wat temp does ,Iron oxide, aluminum, baking soda, table salt melt? degress F please. and about how hot does a US conventional gas stove get? thanks. and aluminum foil is pure aluminum right?

Are the world's glaciers melting? I expect some are melting, some are growing, and all are moving, but all together, what is going on?

Today is the great melting day in Oslo. The icicles from the roofs are finally yielding, and there is a constant dribbling down the walls, with the occasional, hazardous crash when a bigger piece of ice breaks off and smashes into the pavement. It is our first sign of approaching springtime...

1. When the ice cube melts, will the water level rise, stay the same or fall? and why? 2. What happens to the height of pond when ancor thrown overboard rise, stay same or fall? Why? I know that for the first question it's stay the same and for the 2nd question, it's fall; but i don't know...

How much ice could be melted by 320. grams of water at 68.0 degrees C? Would I us mL + mcT=0 for the equation, and do the latent heat of ice for the first part and water for the second?