In: Chemistry
Consider the following reaction at 298 K: C(graphite)+2CL(g)------> CCl4(l) delta H=-139 kj
Calculate
delta S sys
delta S surr
delta S univ
entropy data ( J/mole.K) : C ( graphite) : 5.7 Cl2 (g):223.81: CCl4 : 216.4
the reaction is C(graphite)+ 2Cl2(g) ------>CCl4(l)
entropy change = Sum of entropy of products- { sum of entropy of reactants}
1, 2 and 1 are coefficients of CCl4(l), Cl2(g), C(graphite)
= 1*216.4-{1* 5.7+2*223.81}=-236.92 J/mole.K
Since during the reaction, enthalpy change is -ve suggesting that heat is evolved and surroundings gain entropy
entropy change of surroundings= +139*1000/298.15=466.21 J/Mole.K
entropy change of universe= entropy change of surroundings+ entropy change because of reaction =466.21-236.92 =229.29 J/mole.K