From the following data, c(graphite) + o2(g) ⟶co2(g) δh°rxn = −393.5 kj/mol h2(g) + 12 o2(g) ⟶h2o(l) δh°rxn = −285.8 kj/mol 2c2h6(g) + 7o2(g) ⟶4co2(g) + 6h2o(l) δh°rxn = −3119.6 kj/mol calculate the enthalpy change for the reaction 2c(graphite) + 3h2(g) ⟶c2h6(g

Explanation:

Hi!

Ur Data

C(graphite) + O2(g) --> CO2(g) ΔH = -393.5 kJ

H2(g) + 0.5 O2(g) --> H2O(l) ΔH = -285.8 kJ

2 C2H6(g) + 7 O2(g) --> 4 CO2(g) + 6 H2O(l) ΔH = -3119.6 kJ

calculate the enthalpy change for the reaction

2 C(graphite) + 3 H2(g) --> C2H6(g) ΔH = ?

take

2 C2H6(g) + 7 O2(g) --> 4 CO2(g) + 6 H2O(l)

and inverse it:  

4 CO2(g) + 6 H2O(l) ---> 2 C2H6(g) + 7 O2(g)  when you inverse it you change the AH aswell to a + sign. ΔH =  + 3119.6 kJ

Multiply with 4 the reaction:

C(graphite) + O2(g) --> CO2(g) ΔH = -393.5 kJ

that would give you:  

4C(graphite) + 4O2(g) --> 4CO2(g) ΔH = -393.5 kJ * 4 = -1576 kj

then multply with 6 :  H2(g) + 0.5 O2(g) --> H2O(l) ΔH = -285.8 kJ

that would give you:

6H2(g) + 3 O2(g) --> 6H2O(l)  ΔH = -285.8 kJ * 6    -->  ΔH = -1710 kJ

ur reactions are:

4C(graphite) + 4O2(g) --> 4CO2(g) ΔH = -393.5 kJ * 4 = -1576 kj

6H2(g) + 3 O2(g) --> 6H2O(l)  ΔH = -285.8 kJ * 6    -->  ΔH = -1710 kJ

4 CO2(g) + 6 H2O(l) ---> 2 C2H6(g) +   7 O2(g) ΔH =  3119.6 kJ

4C + 6H2 > 2 C2H7   AH= -1872 kj     but you want 2 C(graphite) + 3 H2(g) --> C2H6(g) so multiply it with 1/2 and ur reaction is:

2C + 3H2 > C2H7   AH= -1872 kj * 1/2 = -936 kj

Answer= -936 kj

Hope this helps you a bit

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."

може ли да зареждате повече информация, моля