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Dacron is continuous filament yarn used ...

Dacron is continuous filament yarn used in curtains, dress fabrics and pressure fire hoses. The reaction for preparing Dacron is by the combination of which of the following?

A

Hexamethylene diamene and adipic acid

B

Caprolactum

C

Phenol and formaldehyde

D

Ethylene glycol and terephthalic acid

Text Solution

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The correct Answer is:
D
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Free energy, G=H-TS, is a state function that includes whether a reaction is spontaneous or non-spontaneous. If you think of TS as the part of the system's energy that is disordered already, then (H-TS) is the part of the system's energy that is still ordered and therefore free to cause spontaneous change by becoming disordered. Also, DeltaG=DeltaH-TDeltaS To see what this equation for free energy change has to do with spontaneity let us return to relationship. DeltaS_("total")=DeltaS_("sys")+DeltaS_("surr") = DeltaS + DeltaS_("surr") (It is generally understood that symbols without subscript refer to the system not the surroundings.) DeltaS_("surr")=-(DeltaH)/T , where DeltaH is the heat gained by then system at constant pressure. DeltaS_("total") = DeltaS -(DeltaH)/T rArr TDeltaH_("total")=DeltaH-TDeltaS rArr -TDeltaS_("total") =DeltaH-TDeltaS i.e. DeltaG=-TDeltaS_("total") From second law of thermodynamics, a reaction is spontaneous if DeltaS_("total") is positive, non-spontanous if DeltaS_("total") is negative and at equilibrium if DeltaS_("total") is zero. Since, -TDeltaS=DeltaG and since DeltaG and DeltaS have opposite signs, we can restate the thermodynamic criterion for the spontaneity of a reaction carried out at constant temperature and pressure. If DeltaG lt 0 , the reaction is spontaneous. If DeltaG gt 0 , the reaction is non-spontanous. If DeltaG=0 , the reaction is at equilibrium. In the equation, DeltaG=DeltaH-TDeltaS , temperature is a weighting factor that determine the relative importance of enthalpy contribution to DeltaG . Read the above paragraph carefully and answer the following questions based on above comprehension: Which of the following is true for the reaction? H_(2)O(l) H_(2)O(g) at 100^(@) C and 1 atmosphere?

Free energy, G=H-TS, is a state function that includes whether a reaction is spontaneous or non-spontaneous. If you think of TS as the part of the system's energy that is disordered already, then (H-TS) is the part of the system's energy that is still ordered and therefore free to cause spontaneous change by becoming disordered. Also, DeltaG=DeltaH-TDeltaS To see what this equation for free energy change has to do with spontaneity let us return to relationship. DeltaS_("total")=DeltaS_("sys")+DeltaS_("surr") = DeltaS + DeltaS_("surr") (It is generally understood that symbols without subscript refer to the system not the surroundings.) DeltaS_("surr")=-(DeltaH)/T , where DeltaH is the heat gained by then system at constant pressure. DeltaS_("total") = DeltaS -(DeltaH)/T rArr TDeltaH_("total")=DeltaH-TDeltaS rArr -TDeltaS_("total") =DeltaH-TDeltaS i.e. DeltaG=-TDeltaS_("total") From second law of thermodynamics, a reaction is spontaneous if DeltaS_("total") is positive, non-spontanous if DeltaS_("total") is negative and at equilibrium if DeltaS_("total") is zero. Since, -TDeltaS=DeltaG and since DeltaG and DeltaS have opposite signs, we can restate the thermodynamic criterion for the spontaneity of a reaction carried out at constant temperature and pressure. If DeltaG lt 0 , the reaction is spontaneous. If DeltaG gt 0 , the reaction is non-spontanous. If DeltaG=0 , the reaction is at equilibrium. In the equation, DeltaG=DeltaH-TDeltaS , temperature is a weighting factor that determine the relative importance of enthalpy contribution to DeltaG . Read the above paragraph carefully and answer the following questions based on above comprehension: For the spontaneity of a reaction, which statement is true?