Two Moles Of Gas A Spontaneously Convert To Three Moles Of Gas B In A Container Where The

How can endothermic reaction be spontaneous?

''Spontaneous reactions are reactions which take place on their own''.This is true. But, Chemistry defines 'spontaneity' in this way.''A chemical reaction is spontaneous iff the gibbs free energy associated with it is negative.''ΔG = ΔH - TΔS :(For spontaneity, ΔG<0)If this number is negative, then the reaction performs work (Endothermic) otherwise, work is being done on the reaction from an external source (Exothermic). For an endothermic reaction, ΔH is positive. The change in enthalpy of a reaction can be generally understood as the change in heat of a reaction. (If this change is negative, the system gives off heat energy; the reaction is exothermic. If the change in enthalpy is positive, the system absorbs heat energy; the reaction is endothermic).With ΔH>0, ΔS must be positive and T relatively large for an endothermic reaction to be spontaneous.Example: Dissolving salt in water.If you pour table salt into a container of water, the salt dissolves on its own. Enthalpy increases. Entropy increases even more. (Since, you have increased the disorder of the system).The reaction is both endothermic and spontaneous at standard temperature and pressure.CONCLUSION: If the change in Entropy at a given temperature is sufficient to overcome the unfavorable change in Enthalpy then the reaction will spontaneously occur thus endothermic reactions are possible. Thanks for the A2A Syed Sumaid Ali

For a reversible reaction, if the concentration of the reactant is doubled, what will the equilibrium constant be?

Change in concentration, pressure, catalyst, inert gas addition, etc. have NO effect on Equilibrium CONSTANT. Only temperature does. Temperature, concentration, pressure, catalyst, inert gas addition lead to a shift in EQUILIBRIUM POSITIONThe equilibrium constant, K is to be kept constant. To keep it constant, “imposed stress” is undone by change in equilibrium position. If a system at equilibrium is subjected to some change in concentration, pressure, temperature, etc., the equilibrium is altered and the reaction takes place in some direction until the system returns to equilibrium once again. There takes place, a shift in equilibrium “position”.A system in equilibrium is affected by the following factors:Change of concentration of any reactant or productChange of temperature of the systemChange of pressure of the systemAddition of catalystAddition of some inert gas

How many moles of water can be made from 4 moles of oxygen gas and 16 moles of hydrogen gas? What is the limiting reagent?

O2+ 2H2 → 2H2OThe process for determining limiting reactant/reagent isTake the moles of one and multiply by the mole ratio of it to the other reactant, and check to see whether the amount you get is higher or lower than what you have, if the number you calculated is higher, then the reactant you started with is in excess, and the other will be the limiting reactantTake the limiting reactant and multiply by the mole ratio of it to the product in question and you have your answerExample —So you have 4 mol of O2, 16 mol H2, the mol ratio in the equation is 2 mol H2/1 Mol O2, so taking the 4 mol O2 and multiplying by 2 mol H2/ 1 Mol O2 will cancel out the mol O2 and gives you 8 mol H2 needed, meaning that o2 is the limiting reactant with 8 mol of H2 remainingNext step — take the 4 mol of O2 and multiply by 2 mol H2O / 1 Mol O2, and you get 8 mol H2O produced by this reactionHope this helps, good luck!