if you heat a powder sample what will happen to the spacing in the x ray diffraction pattern?
408015
If you heat the powder the spacing in the x-ray diffraction pattern will decrease.  Most any powder used in x-ray diffraction will be made up of grains with millions of atoms.  And, the atoms in the grains will be arranged in a definite crystal lattice.  So, there will be a definite diffraction pattern.  And, heating the powder will generally increase the spacing between the atoms.  The spacing in the diffraction pattern is inversely proportional to the distance between atoms in the lattice.  So, heating the powder will tend to decrease the spacing in the diffraction pattern.
367833
Are you implying that the marks are evenly space? In that case the volume on the flask decreases  spacing should increase.
388409
You can take many physical and sensory measurements on the dried materials before and after the experiment, such as crystal structure, color, odor, density, pH, approximate hardness/strength (i.e., resistance to grinding). \nYou can measure the temperature it reached when boiling and look up the decomposition temperature in the Handbook of Chemistry and Physics if you can find a copy; probably can find something like it on web. Look up boiling point of solution and be sure you use one of the strengths you find in the actual solution; compare to actual boiling point.\nDepending on the type of sugar, you might be able to use Benedict's test for sugar (ref.)
81841
Depends on the crystal structure of the alloy they constitute
141648
It is formed by heat pressure
398076
if the powder size is quite small, eg grains to dust, it can spontaniously explode in air.  Otherwise it just "rusts" to get a layer of oxide like most metals.
951269
For all practical purposes, if a solution is saturated (can not dissolve any more) it is full and all others will fall to the bottom, undissolved. \n\nRealistically a small (very small) amount of the other powder could dissolve if it had different enough properties.
970108
it will speed up the reaction since the heat rises the temperature.\nit will also decompose a compound to its elements--decomposition reaction.
882835
Probably carbon latice structures, like buckeyballs or nanotubes.  These could then contain the smaller compounds that are doing the desired work.
37650
Yes.\n\nOrthoclase feldspar is an example.  At high temperatures, Fe will fit into the orthoclase lattice.  As temperature drops, the lattice shrinks so that Fe no longer fits.  Fe diffuses out of the latice and accumulates along the planes between orthoclase crystal twins.  Along the way, it grabs O to produce Fe2O3.  If you look closely at pink granite, usually you will see that the pink grains are actually white and red striped.  Those grains are orthoclase crystals with exsolved hematite along twin planes.\n\nExsolution and diffusion of Fe from orthoclase can only occur at high temperature.  If the orthoclase cools too quickly for the Fe to diffuse out, it will remain in the orthoclase lattice, which will be distorted to accomodate the larger (larger than K) Fe ion.\n\nMaterial science is not boring.
775471
I think the cooling effect is the same as heating effect, but opposite of it. If so, then find out the coefficient per degree Celcius of that particular material.\n\nThe formula will be = difference in volume change / the original volume x difference in temperature change = coefficient per degree Celcius. Just reduce the minus (-) sign and treat it as positive even though we know it's reduced.\n\nThen find out if this material is one straight line/rod. If it's in square, then the volume change will be 2x. If cubic, 3x.\n\nDifferrent material have different coefficient. Liquids, solids, gases... Even different solids have different coefficient.\n\nAlso pay attention to...\nDensity = Mass/Volume\n\nI can't guarantee the accuracy but I hope this helps.
174475
mix it...let NaCl dissolve in water...then let the mmixture evaporate or perhaps bring the mixture into a boil 'til you can see the formation of crystals...   try it... i've encountered such experiment in my chemistry class... im not quite certain of the procedures though...it's two years ago...cant remember it well...^_^
445950
As the metal flexes, the molecules which make up the compound are temporarily displaced and generate kinetic energy which is dissipated as heat.   The process can be demonstrated in reverse i.e. when metal is heated, the molecules are displaced and the metal becomes pliable
851633
Stirring during refluxing will maintain the solution that is being heated. It will dissolve any solid particles into the solution and prevent and layers from being formed in the solution between liquids with different densities. It will also guarantee that the solution is being completely heated and that you're not burning the bottom of the solution.
388144
That's a trick question; the lattice parameter changes as the crystal passes through an "order-disorder transition", but only by around 0.04%.\n\nThe nearest neighbour distance is 2.531 Angstroms, which corresponds to a lattice parameter of 3.580 (I believe) for this type of lattice (Cu3Au, which is essentially face-centered cubic).
883855
The samples must be homogenously ground to enable the solvent to fully soak into the sample and extract the compound you want in question. Also there is a question of statical averages so a uniformed powder sample is the best for this process. If the sample is lumply or too big the solvent can't fully soak into it and wherefor not all of your compound in question is extracted by the process (Then the solvent fills up the soxhlet thumbie (sp)). If this happens you will get a incorrect value then you come to do the maths in determinating the amoult of the coumpound in question.
809008
is this your school homework,  are there suppossed to be other questions before these because my computer shows them starting from No. 4.\nnway,\n4.  filter the solution while still hot because as the soltion cools crystallization occurs, and you will nloose your product on the fiolter paper.\n5. crystallization can be induced by reduction in temperature i.e put in an ice bath or you can use a technique called seeding where you put a few crystals of the expected substance in the solution, the other method is to increase the concentration of the solution by evaporating it, to saturation point, ensure you do not evaporate it dry.\n6.i do not know what you started with so i can not tell.\n7.slow cooling will definately give bigger crystalls.\n8.sodium chloride reacts with silver nitrate to form a white precipitate, actually silver nitrate solution is used to analyse NaCl in industrial setting.\n\nope you will find these information sufficient.