At what temperature is Chlorophyll destroyed. I can't  find a boiling point for it ... if it even has one.
489914
Chlorophyll is a rather complex and most of all large molecule, which means that the pure substance will be a solid.   In a leaf the chlorophyll is in solution.\n\nLeaves turning brown most likely involves encymatic digestion of parts of the molecule. The core construction of chlorophyll is quite hardy - a flat system of five- or six-atom rings with a central magnesium ion held in place by nitrogen atoms pointing to it in a square. (Hemoglobine and one of the vitamins have a similar basic structure, hemoglobine with iron in the centre and the vitamin with cobalt.)\n\nYou can dry a leaf and keep the chlorophyll intact at temperatures up to 120°C without any browning effect. Such a dried leaf will remain green, unlike a wet leaf where encymatic digestion will destroy the pigment.\n\nThe leaf will turn brown at temperatures where paper also begins to turn brown - when the cellulosis of the plant cells begins to split off water. This may start around 451°F...
975732
Substance: Water\nLatent Heat Melting J/g:  335\nMelting Temp°C: 0\nLatent Heat Boiling J/g:  2272\nBoiling Temp °C: 100 \nHeat of vaporization (kJ/mol): 40.65
319025
Yes a big problem. Ever hear of the "boiling frog"? If you throw a frog into a boiling pot of water it will freak out, try to escape, and eventually die. BUT... if you put a frog into a cool pot of water turn the burner on and let it reach a boil, the frog will fall asleep in the warming water and then die as it boils. Wake up everybody, we're warming up, don't fall asleep! P.S. all you literal jerks out there.. this is a metaphor. Frogs biologically will respond. If they are able to jump from the container when it heats up, they will. Where are we gonna jump?
844268
how were you measuring the pH? if it was a pH meter maybe it wasn't calibrated correctly/ recently?? or if it was with litmus paper.... maybe it went bad? I'm not sure if it can... check and see if there could have been an expiration date. i don't think temperature would have that drastic of an effect unless you did the experiment at pH7 and a seriously high (like about 60C) temp and the other ones at room temp or 37C (body temp)... sorry i cant help anymore then that, that's very strange!
933014
All decent explanations so far; I hope I can add to what has already been posted.\n\nLiquid and Ice most definitely can exist at the same temperature and Ice can be and often does get colder than 0C.\n \nFirst of all the Triple Point of water is the pressure and temperature at which Ice, Liquid Water and Water Vapor exist at the same time in equilibrium.  Vapor is the right word, not steam although you can argue that the only time that Water Vapor and Steam are the same thing is at a very low pressure.  The Triple point of water only happens at a near perfect vacuum, 0.0063 ATM to be precise.\n\nAdding Salt to water will lower the freezing point, but then it isn't water anymore, it's salt water.  Even so, Liquid Salt Water and Ice Salt Water can also exist at the same place and time at the same temperature, slightly below 0C.  But let's stick to water.\n\nIce can easily be lower than 0 degrees.  Consider a bucket of water, liquid water sitting outside and the air temperature is -10C.  Little by Little, as the liquid reaches 0.0098 C, liquid starts to become ice.  The ice crystals form in the bucket, around the walls of the bucket and on the surface first.  The air is still -10C so the bucket, the liquid and the ice will keep getting colder.  The ice on the surface will drop to slightly below 0C but very slowly since it is still absorbing the heat of the not-yet-frozen water.  Eventually, the entire bucket of water will be frozen and will be just below 0C.  First the walls of the bucket will reach -10C (same as the air tempertaure).  The ice near the walls of the bucket and on the surface will reach -10C first, continually absorbing the heat energy from the relatively warmer ice near the center of the bucket.  Until finally, the entire bucket of ice is steady at -10C.  That is until the sun comes out or the day gets warmer.\n\n\nAnd by the Way, dry ice is not water, it's frozen CO2 (Carbon Dioxide)\n\nOne more thing, at a near perfect vacuum, you can actually cool liquid water to less than 0C without it freezing.  Never tried that but I did accidently freeze a beer last night...
730844
OK...You can start with the equation of DG (I'm using D instead of writing "delta").\n\nDG = DH -TDS  You've seen that equation, right?  OK..Since the boiling point of water is 100 degreed C at 1 atm pressure, we are really talking about an equilibrium situation.  So, DG= 0.\n\nConsequently, DH = TDS.  \n\nSince you know DH and you know T (in Kelvin), you can calculate DS.  Make sure that you convert DH into Joules (instead of kilojoules) before you finish the problem.
1174986
100C:::: Pure water boils at exactly this temperature.\n37C:::::: Normal Human body temperature\n0C:::::::: Pure water freezes/melts at exactly this temperature
845318
Things have unique color because they reflect and absorb light frequencies differently.  Green chlorophyll absorbs all of the other component colors of the visible spectrum and only reflects green light; therefore, we say 'it's green.'\n\nYou might still ask, "...but why?" and the answer would probably be one that describes the atomic/molecular components of chlorophyll and their their particular physiologic properties.\n\n(((( r u randy? ))))\n.
102721
I won't do your homework for you, but I will give you a few hints.\n\nThe first hint is that ddnight is talkin' smack. This has nothing to do with atmosoheric composition.\n\nThe second hint is that you should be looking very varefully at the relative effect of C4 and CAM utilisation on water LOSS. Underline the word 'loss".\n\n--------------------\n>>>CAM plants and C4's do better in higher temps than C3's.\n\nGenerally yes. But the question is why the plants died in that order. Begonia are tropical plants, so a temperature would not have killed it, and the pineapple is both tropical nad C4, sdo temperature effects can't be at play directly.\n\nOnly one plausible explanation remains.
986566
Hello friend.. \nHope you have heard of chlorophyll and other colouring (pigments) agents naturally present in plant leaves.Chlorophyll is the chief chemical helping reactions that finally end up in production of starchy food in plants. \nThese chlorophylls themselves break down and  are being continually used up in the food-manufacturing process. \nBut while the plant grows the plant resynthesizes this pigment and  leaves seem green.\nBy the end of  summer, cells called cork cells, which are degenerate products, get accumulated in the base of the leaf-stump. This results in blockage of water transport to leaves through their "veins".  Chlorophyll from then on degenerates and breaks down. \n    In the fall (autumn as we call it here), seasonal changes slow down the rate of  chlorophyll-synthesis.\nCarotenoids which are another group of pigments present in leaves become clearly visible through these leaves devoid of Chlorophyll. Light is not needed in order for a plant to produce carotenoids, therefore these pigments are always present in a living plant. Aspen, Black Cherry, Sycamore,  Maple and  Poplar are some of the trees famous for their pictureque beauty in Autumn. Carotenoids appear in colours ranging from Brown or red to yellow depending on its concentration in these leaves.  Examples of carotenoids found in leaves include lycopene, which is red, and xanthophyll, which is yellow.  When found naturally, carotenoids give colour to carrots, beetroot, and a number of plant and animal produces like mango, banana egg yolks etc.\nBesides these natural Carotenoids, there are a group of pigments called Flavanoids that appear in the leaves only during autumn. Examples of flavonoids include flavone and flavol, which are yellow, and the anthocyanins, which may be red, blue, or purple, depending on pH (strawberry, apple,  cherry etc..)Anthocyanins are the chief agents among these flavanoids. They are a result of degeneration of sugar moieties in leaves. In autumn, as a plan to prevent losing precious minerals, ions and vitamin-enzymes through falling leaves, these chemicals are transported into the trunk/stem of the plant. But Carbohydrates, being complex molecules aren't transpoted to the main stem/trunk. The transport of ions back into stem causes a  fall in the phosphate concentration in the leaves,which in turn triggers production of Anthocyanins. This process is dependent on physical influences like soil-acidity and brightness of Sun light. Brighter, the days, brighter the colour of autumn leaves and vice versa.\nLeaves containing primarily anthocyanins will appear red. Leaves with good amounts of both anthocyanins and carotenoids will appear orange. Leaves with carotenoids but little or no anthocyanins will appear yellow. In the absence of these pigments, other plant chemicals also can affect leaf color. An example includes tannins, which are responsible for the brownish color of some Oak leaves. \nHope that clears your doubt.\nbye..
307996
There are actually 2 types of chlorophyll, named a and b. They differ only slightly, in the composition of a sidechain (in a it is -CH3, in b it is CHO). Both of these two chlorophylls are very effective photoreceptors because they contain a network of alternating single and double bonds, and the orbitals can delocalise stabilising the structure. Such delocalised polyenes have very strong absorption bands in the visible regions of the spectrum, allowing the plant to absorb the energy from sunlight.\n\nThe different sidegroups in the 2 chlorophylls 'tune' the absorption spectrum to slightly different wavelengths, so that light that is not significantly absorbed by chlorophyll a, at, say, 460nm, will instead be captured by chlorophyll b, which absorbs strongly at that wavelength. Thus these two kinds of chlorophyll complement each other in absorbing sunlight. Plants can obtain all their energy requirements from the blue and red parts of the spectrum, however, there is still a large spectral region, between 500-600nm, where very little light is absorbed. This light is in the green region of the spectrum, and since it is reflected, this is the reason plants appear green. Chlorophyll absorbs so strongly that it can mask other less intense colours. Some of these more delicate colours (from molecules such as carotene and quercetin) are revealed when the chlorophyll molecule decays in the Autumn, and the woodlands turn red, orange, and golden brown. Chlorophyll can also be damaged when vegetation is cooked, since the central Mg atom is replaced by hydrogen ions. This affects the energy levels within the molecule, causing its absorbance spectrum to alter. Thus cooked leaves change colour - often becoming a paler, insipid yellowy green.
165423
A grain of salt.  It won't dissociate under physical pressures except for extreme temperature (800 Celsius) but will dissociate into sodium and chlorine ions in the presence of water.
65931
Depends upon the product.  Some contain preservatives, some do not.\nSodium copper chlorophyllin derived from the alfalfa plant is relatively stable.  Some products add methylparaben and propylparaben (derived from benzoic acid) to preserve the product.  These solution have shelf lives of up to one year.\nExperiments with liquid chlorophyll solution show that even when they decompose (stored in heat and light), they form no toxic products.\nYour product may have an expiration date on it.  The solution should be useable for at least six months past that date.
949698
Chlorine is required in photosynthesis as an enzyme activator during the production of oxygen from water (13).\n\nAn excess of chlorine will result in burning of leaf margins and pre mature loss of leaves
97853
rice,wheat,potato,etc...r some of the C-3 plants.....when they r exposed to co2(14),they produce 3C compound called phosphoglyceric acid.....this occurs only in mesophyll cells at an optimum temp of 20-25 degree C. Here photorespiration rate is high & leads to loss of fixed CO2. It also decreases CO2 fixation rate....
244526
Plant cells contain chlorophyll. There are a few types of chlorophyll. Some are high energy and others lower energy.  Every species of plant has different ratios of these various chlorophyll molecules.\n\nAs light energy hits a plant leaf, you get conversion of energy. If more light hits the plant, then more energy up to a point. You will reach a couple of roadblocks. The first is the theoretical maximum the chlorophyll can produce. You have saturated it and it can do no more. I say theoretical as this level will often burn the plant before it is reached. The other roadblock is that as you increase the energy you may move or shif out of the optimal range for that species. So they may have lot of chlorophyll A and little Chlorphyll C and if you shifted to the energy wavelength of C total energy production would decrease even though you increased available source energy.\n\nSince this sounds like a school project, I will only point you in the proper directon.  Look up different types of chlorophyll. Look up the types found in tomato plants. Both are easily searched on Yahoo or Google. Then look up evergy levels of saturation on those types and then look up ebergy levels of light intensity. You could then make a simple chart showing at what level the prduction will shift and then decrease.
1106381
You still haven't answered the question. What do you mean by hottest temperature range? And are you referring to the temperature range of the spores or the adult plant or the leaves or what?\n\nThe question has no meaning. I could name any plant species in the world and it would probably be the most heat resistant under some circumstances.\n\nThink very carefully about what information you actually want and then ask for that information. Saying that heat reistant means temperature range hasn't clarified anything.\n\nOh, and ignore mufuonamoto, he is  talking rubbish. Eucalypts are NOT native to California, they are native to Australia and nearby islands and were only taken to California a little over 100 years ago.\n\nNot only aren't euclaypts fire resistant , a great many euclaypts will die if they are exposed to fire.\n\nNeedless to say the idea that any plant only sprouts after fire is absolute nonsense.