Question

Nitric oxide (NO) can be formed from nitrogen, hydrogen and oxygen in two steps. In the first step, nitrogen and hydrogen react to form ammonia:
N2(g)+3H(2)-->2NH3(g) H= -92. kJ

In the second step, ammonia and oxygen react to form nitric oxide and water:
4NH3(g)+5O2(g)-->4NO(g)+6H2O(g) H= -905. kJ

Calculate the net change in enthalpy for the formation of one mole of nitric oxide from nitrogen, hydrogen and oxygen from these reactions.
Round your answer to the nearest
.

Answer 1

Question #85305, Chemistry / General Chemistry | for completion

Nitric oxide (NO) can be formed from nitrogen, hydrogen and oxygen in two steps. In the first step, nitrogen and hydrogen react to form ammonia:

N2(g)+3H(2)-->2NH3(g) H= -92. kJ

In the second step, ammonia and oxygen react to form nitric oxide and water:

4NH3(g)+5O2(g)-->4NO(g)+6H2O(g) H= -905. kJ

Calculate the net change in enthalpy for the formation of one mole of nitric oxide from nitrogen, hydrogen and oxygen from these reactions.

Round your answer to the nearest

Answer:

N2(g)+3H(2)-->2NH3(g) H= -92. kJ

4NH3(g)+5O2(g)-->4NO(g)+6H2O(g) H= -905. kJ

The law of Hess is the basic law of thermochemistry, which is formulated as follows: The thermal effect of a chemical reaction carried out in isobaric-isothermal or isochoric-isothermal conditions depends only on the type and state of the starting materials and reaction products and does not depend on the way it proceeds.

Therefore,

Htotal=H1+H2

Htotal= -92 +(-905)= -997 kJ.

Answer provided by www.AssignmentExpert.com