In a reaction involving cobalt(II), how do you know if it's endothermic or exothermic?
596796
Exothermic reactions produce heat, so the temperature of the reactants will become higher, i.e. hotter.\n\nEndothermic reactions absorb heat from the surroundings, so the temperature of the reactants will become lower, i.e. colder.\n\nFor a specific reaction involving Co(II), would have to know the reaction equation and then calculate the delta enthalpy.
923645
No, it's an endothermic reaction meaning you need to add heat (but no necessarily a flame) to drive the reaction. The only way it would react with oxygen in the atmosphere is if the outside temperature where hot enough to drive the reaction. Of course, we'd all be dead, so we couldn't see it.
829949
energy input: reaction requires energy to take place - endothermic\nenergy output: reaction gives off energy when it takes place - exothermic
196178
It is exothermic when the rxn. Heat is negative\nConsider Thermite\n\n2Al(s) + Fe2(O3)(s) –> Al2(O3)(s) + 2Fe(l) ∆Hºrxn=-847.6kJ
727069
exothermic means energy is given off, so it wud have a - sign\n\nendothermic means energy is absorbed and wud hav a + sign\n\nhope this helps!!
984574
Endothermic reactions are ones that take energy from their surroundings.  They are not usually spontaneous.\nExothermic reactions release energy into their surroundings and usually are spontaneous.
64647
2x (G2 + M2 ---> 2GM)      DH=-280.0*2= -560.0 kJ\n2x (L + 2M2 ---> LM4)      DH=-350.0*2= -700.0 kJ\n   (L2G4 ---> 2L + 2 G2)   DH=122.0*(-1)=-122.0 kJ (change sign when flip over)\n\nAdd them together, we'll have:\n2G2 + 2L + 6M2 + L2G4 ---> 4GM + 2LM4 + 2L + 2G2\nthen cancel 2G2 and 2L on both side, we end up with:\nL2G4 + 6M2 ---> 2LM4 + 4GM\nthe enthalpy of this reaction is, therefore the sum of each enthalpies calculated above.\nDH=(-560.0) + (-700.0) + (-122.0)= -1382.0 kJ (exothermic process)\nhope that'll help!
621304
If you are dealing with a reaction involving ammonium carbonate in solution, and are then measuring the temperature rise, you need the heat capacity of water, not ammonium carbonate!\n\nPlease post the whole problem if that is not enough to get you started.
390022
the reaction is exothermic because the resultant solution or products is warmer than the reactants, assuming that it didn't warm up in the enviroment. In addition all neutralisation reactions are exothermic.\n\nThe solutions were mixed rapidly so that the concentration gradiant increases as quickly as possible preventing the reactants absorbing the heat from the reaction before the reaction is finished.  ie the initial rate of reaction being as high as possible.
908972
Any combustion reaction is exothermic.\nSo a and b are exothermic.\nc is the dissociation of water, which involves breaking bonds, so it is endothermic.\nI think d is supposed to represent the melting of ice, which again takes in heat.
395234
if you go from A to be and then B to A you should have no overall energy change. one will be an exothermic reacion and the other should be endothermic reaction
761935
when in a chemical reaction
980614
Most reactions are exothermic.\nExamples are\n\n1) Combustion of methane (natural gas).\n\n2) Neutralisation of dilute hydrochloric acid and dilute sodium hydroxide.\n\n3) Adding concentrated sulphuric acid to water is highly exothermic\n(gives out a lot of heat).\n\n4) Adding water to anhydrous copper(II) sulphate is exothermic.\nAnhydrous copper(II) sulphate is white.\nAnhydrous is pronounced "an-high-drus"\nAnhydrous means "without water".\n\nAnhydrous copper(II) sulphate is copper(II) sulphate which is completely dry.\nWhen water is added to it, it turns into the familiar hydrated blue crystals.\nHydrated is pronounced "high-dray-tid", it means 'with water'.\nThis is used as a test for water.\n\nIf blue (hydrated) copper(II) sulphate crystals are heated,\nan endothermic reaction occurs, they lose their water,\nturn white and become anhydrous copper(II) sulphate crystals again.\nThe reaction is reversible.\nBlue copper(II) sulphate crystals will also turn white in the presence of  concentrated sulphuric acid.\n\n \n\nFew reactions are endothermic.\nExamples are\n\n1) Photosynthesis.\nChlorophyll is a very clever catalyst,\nwhich allows plants to make sugar from carbon dioxide in the air.\nThe energy needed for the reaction comes from sunlight.\n\n2) The reaction of ethanoic acid with sodium carbonate.\n\n3) Dissolving some salts in water is an endothermic process.\nPotassium chloride and ammonium nitrate\nboth take in energy when they dissolve.\nIf you put a thermometer in the solution as they are dissolving,\nyou will see that the temperature drops.\n\n4) Melting, boiling and evaporation\nare all endothermic processes (not reactions).
505382
At that temp, we have\n\nCaCO3 -> CaO + CO2\n\nCaO + 2NaCl -> CaCl2 + Na2O\n\nA lot of other side reactions will occur.
730330
Different chemical composition, one has a reaction the other doesn't..☺
1120784
Well to start off any reaction that produces oxygen is potentially combustible, especially one that requires energy (endothermic) so be careful.\n\nTwo suggestions: \nFirst, electrolysis, this is where you break the covalent bond between oxygen and hydrogen with electricity (energy).  The by products are oxygen and hydrogen gas.\n\nMy second idea is simple rust.  Put iron (Fe) into water (H2O) and you will produce Iron-oxide or rust.  The Oxygen combines with the iron.\n\nGood luck.
1075772
the covalent reaction it undergoes is a dehydration reaction