Are these reactions are exothermic or endothermic?
440509
There are many types exothermic or endothermic reactions.\n\n Exothermic reactions.\n1.Combustion reactions.(Except combustion of Nitrogen.)\n2.Combination reaction of anions & cations.(Ex-OH- + H+)\n3.Reaction of metals with non-metals.\n4.Some(1st) Electron affinity reactions(Expect elements of S2,P6,d10;Nitrogen)\n\n Endothermic reactions\n1.All the ionization reactions.\n2.Bond breaking reactions.\n3.Breaking into anions,cations.\n4.All the Sublimation,Vapuorization,Atomization reaction.\n5.(1st)Electron affinity reactions of S2,P6,d10 elements;Nitrogen\n6.All the 2nd,3rd electron affinity reactions \n\nSo,(a) is a exothermic  reaction\nAnd,(b) is also exothermic reaction
239811
exergonic releases heat and endergonic take in heat...they both use ATP or some form of energy. They are both chemical reactions dealing with heat
871220
The second one:\nAF + H --> AFM + TM\n\nActivation E: +10KJ/mol is moderate\nHeat of Rx= +5.2 KJ/mol is positive, making this an endothermic reaction (requires the input of heat or energy to accomplish).\n\nSee the site below:
239222
no, reaction times are too slow at that temperature.  (I'm just guessing, but I'm a chemist.  You should be able to look up reaction energies, try Beilstein.)
482502
Must be endothermic.\nA picture's worth a thousand words...
701443
1 - the reaction is reversed and multiplied by 4, so the enthalpy change is 11508 kJ\n\n2 - The reaction is a combination of the other three (I'll label them A, B and C, in the order you have them listed, for simplicity)\nThe original reaction = 2A - 2B -2C (the first one is just doubled, the next two are doubles and reversed), so 2*321.8 - 2*571.7 - 2*288.6 = -2542.2 kJ\n\n3 - This one is done similarly to question 2.  A - 0.5B + 1.5C\n180.8 - 0.5*(-906.2) + 1.5*(-483.6) = -91.5 kJ\n\nHope this helps
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.
758969
1. This is too big a subject to teach in a few lines.\n2. Enthalpy is the energy of a reaction delta-H (triangle).  The enthalpy of a reaction is the energy given out or absorbed by a chemical reaction.\n\nThis is a simple answer and does not work for large changes in temperature or if a change of state is involved.
730330
Different chemical composition, one has a reaction the other doesn't..☺
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
186407
One way to tell is to look up the heats of formation for the reactants and products.  Add all the reactants up and all the products up.  Subtract the reactants from the products.  If the answer is negative, the reaction is exothermic.  \n\nThe other way is to actually carry out the reaction and see if it liberates heat or not.
920392
it is exothermic, meaning the combustion reaction releases energy in the form of heat
673440
The activation energy of a reaction is different for every reaction and is totaly independant of wether the reaction is exothermic or endothermic. For any reaction to proceed the minimum energy must be equal to or higher than the activation energy.\n\nNow where your question can come in is, i think, is if the reaction is reversible. In one direction the reaction will be exothermic and in the opposite direction the reaction will be endothermic. For both the forward and backward reactions the activation energy is the same and there is nothing that can be done to change that.
613069
1.  There is no process going on in beaker A.\n2.  The process in beaker B is endothermic, as it consumes heat from the surroundings.\n3.  He's studying the heat of solution of sodium nitrate.\n4.  It's negative, as it's an exothermic process (the heat of the system is lower than it was to start, as heat was given off to the surroundings).
315618
(1)FIRST TO KNOW THAT WEATHER REACTION IS EXO OR ENDO-THERMIC .\n(2)QUANTITY OF REACTENTS.\n(3)QUALITY OF REACTANTS.\n(4)TIME OF REACTION.\n(5)TEMP. OF BATH DURING REACTION.\n(6)RATE OF REACTION DURING PROCESSetc etc.
860331
NH4Cl has an enthalpy of solution of +14.8kJ/mol, meaning the reaction is endothermic.
97497
There are temperature changes is most reactions becuase there is heat generated, known as the heat of reaction.