In: Chemistry
Consider these reactions, where M represents a generic metal
1. 2M(s)+6HCl(aq)------>2MCl3(aq)+3H2(g) Delta H1=-749.0 KJ
2. HCl(g)------->HCl(aq) Delta H2=-74.8 KJ
3. H2(g)+Cl2(g)------->2HCl(g) Delta H3=-1845.0 KJ
4. MCl3(s)-------->MCl3(aq) Delta H4=-298.0 KJ
Use the information above to determine the enthalpy of the following reaction.
2M(s)+3Cl2(g)----->2MCl3(s) Delta H=???
2M(s)+6HCl(aq) -----> 2MCl3(aq)+3H2(g) : ΔH1 = -749.0 KJ ----(1)
HCl(g) -----> HCl(aq) ; ΔH2 = -74.8 KJ ----(2)
H2(g)+Cl2(g) -----> 2HCl(g) ; ΔH3 = -1845.0 KJ ----(3)
MCl3(s) ------> MCl3(aq) : ΔH4 = -298.0 KJ ----(4)
Use the information above to determine the enthalpy of the following reaction.
2M(s)+3Cl2(g) -----> 2MCl3(s) ΔH= ? ----(5)
Equ(5) can be obtained from remaining four equations as follows:
Eqn(5) = Eqn(1) + [6xEqn(2)]+[3xEqn(3) ] + [2xreverse of Eqn(4)]
ΔH= ΔH1 +(6xΔH2 ) + (3xΔH3 ) + (2x(-ΔH4 )
= -749 + (6x(-74.8)) + (3x(-1845)) + (2x(-(-298))) kJ
= -6136.8 kJ