Question

In which of the following reactions is A.Sº expected to be positive? Select one: O a. None of these O b. 2CH(9) - 702(9) - 4C02() + 6H 0(1) c. H 0() = 250.(g) —HSO4(1) d. Gali) — Ga(s) e CO2(g) –C023)

Answer 1

O Entropy is determined by the randamness produced y the system. noret Gaseous molecules have targe entropy value followed by liquid and then solid in fact entropy of Solid and liquid are neglected with respect to geo gaseous molecule.. Entropy order & gas riquid> soud. (6) 202 H6C +702(g) 4 Colg) + 6H2O(1) ang = Gascous molecules - Gascous molecule in un product part -parts reactant part, = 4 - (2+7) - -5 AS ang ve, therefore no of gaseous molecules decreases in the reaction. Thus randamness decreases. Therefore entropy decreases, NOSNO Ars .ver one e) H20 (1) + 250, ca s o C Copy e. ang 0-2 -2 I liquids are neglected J Ars= (-) vel (d) Gacion Gals) or () Wino AS liquid has greater entropy than solid state.so in these reaction entropy deereases as nquid Go is transformed into solid Ga. Aps =(-) ve cog(g) 02 (8) Ang = o-15 - 1 . (Aps" = (-) vel As the gaseous coz is tranformed into solid con thas randamness decreases. So entropy decreases in this reaction. Thus none of these reaction occur with positive entropy change ise, geroso. Ar5 = (-ove for all the reaction so option-@ is correct.

2. When a system ubarakes heat by means of any chemical reaction, the process is called exothermic reaction de 4H = -ve. In this type of reaction heating occur.com When a system oborates absorb heat then the reaction is said to be endothermic. In this type of reaction 44 = (tove, thus cooring occur as heat is absorb from the surroundings in the surroundings So, endothermic reaction, cooling occur and and heat is absorb. (If cooling of the system occur the it will be exothermic) on. 1. When NHS Noz dissolve on to cooling of to occur. That means on disolving NHA No3 into H2o heat is absorb from the water. Thus this is a nabäcc. endothermic surrounding = H2O process system = NaNoz) 2. The expansion of real gas un vaccum cooling of the gas occur. This heat is übarated by the gas . Thus it is a exothermic process. (real gas system, vaccum= surroundings) When Liquid water forms ice heat is ribarated by the lig H₂o. Which is called heat of freezing. Thus this occur by exothermic process. C system = water (riquid) ) ), so only 1 process occur in endothermic tast so notion-e is correcto bwoofredo