How do you know if a chemical reaction has taken place?
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If heat has been added to an element, it may make a chemical reaction.  If some object's physical properties due to heat or cooling, a chemical reaction may have occurred.  For example, a fire burning wood creates a chemical reaction in the wood.
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the 4 indicators of a chemical reaction are 1. the formation of heat or light; 2. bubbles; 3. the formation of a precipitate; and 4. a color change\n\nI hope this helps
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Take solutions of each metal ion and pieces of each metal.  Put metal pieces in each solution that does not contain that metal ion and observe whether any reaction is taking place.  Tabulate all observations and you should be able to see quickly which are the most and least reactive metals.
110839
temperature changes de amount of energy in molecules, which has a direct efect on the amount of light transmited through a  solution and, therefore, afects absorbance.  Also, in chemical analysis, the formation of colored compunds is necesary and if the correct temperature is not set, the compound doesn't form correctly. (just some reaction mechanisms from organic chemistry)\nThe AOAC method for testing nitrate content in water is a good example. If you don't give the reaction the correct temperature, the colored compound will never form and the test is invalid.
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The first answer does give an indication, but it is not a definitive test.  Take a sample of the substance, drop acid on it as before, but hold a wet piece of blue litmus paper over the bubbles.  If the litmus turns red, then the gas is CO2, and the substance is a carbonate.
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A reaction tends to be spontaneous if  it causes an increase in the entropy of the system, and/or a decrease in the enthalpy of the system \n\nBoth reactions are endothermic (increase in enthalpy) becuase of positive delta H values.\nBoth have an increase in entropy (positive delta S value for the first one, production of a gas for the second)\n\nSo I'd say statements ll and lll are true.
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GO to wikipedia.com and type in chemical reaction.  That is kind of a tough definition, so I will help to break it down a little for you.  Basically, you got something, and it changes into a whole new a different thing.  That is a chemical reaction.  It could be 2 things coming together to make 1 thing, or vice versa.  Or two things could lead to 2 new things.  The most important part of a chemical reaction is that substances change to NEW substances that have serperate properties and characteristics from the original.\nOn wikipedia there is a link to an IUPAC definition.  IUPAC is pretty much in charge of defining stuff in chemistry, so their definition is the one you're looking for, however, it might be a little complicated.  If this didn't help, maybe you should repost your question.
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Most chemical reactions, both in nature and in the laboratory, take place in a solution.\n\nFor ionic chemicals, it is the polarity of the solvent (usually water) which allows the separation of the ions so that the reaction can take place.\n\nFor non-polar chemicals, the solvent (often a non-polar one) allows for the chemicals to come into contact with one another and to regulate the speed at which the reaction takes place.\n\nAll biological chemistry depends upon reactions which take place in water (as a solvent).  This is especially true of reactions involving enzymes.
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yes, reaction rates are based on several things, concentration and temperature are the most important, because of the water added to the reaction, it will be less "likely" that a vinegar molecule will collide with a baking soda molecule, because of this the reaction will go slower. the way to calculate this is K = [Products]/[reactants].  Where [] is the concentration of each solute present (in moles per liter), and K is the constant value for this perticular reaction, which can be found in a chemistry text book.
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Correct.\nD. when delta G is positive the reaction is non-spontaneous
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A. The mass of each reactant present.\n\nWith the above, you can find the number of moles of each reactant.\n\nFrom the chemical equation of the reaction, you can determine the mole ratio required for the reaction to take place without any excess in either reactants.\n\nYou can then compare the number of moles calculated to the mole ratio and determine the limiting reactant.
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Precipitate if it settles to the bottom of the reaction vessel or flask or a product if it remains in solution.
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It's a Chemical/Fusion reaction...
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Different chemical composition, one has a reaction the other doesn't..☺
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chemical reaction\n\nall substance give off some heat during change\n\nlook up kinetics on the web
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check out the law of conservation of matter. it says that no matter what chemical reaction you look at matter can never be created nor destroyed.\nthat means the number of atoms of each type must be the same before and after a reaction takes place.
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ask in chemistry category