Enthalpy is energy of bonds broken - energy of bonds formed. Here, the NH3 and O2 are broken and H2O and NO are formed. So the energy to break the NH3 bonds is 3 times the amount of energy it takes to break a N-H single bond (because there are three of them in a NH3 molecule) and then multiplied by 4 because there are four particles.
So the energy of the bonds broken is 12x the energy to break a N-H single bond plus 5x the amount of energy to break an O—O double bond (you don’t multiply this by anything because in each O2 molecule there is only one bond).
The energy of the bonds formed is 6*2 = 12 Times the amount of energy for a O-H single bond plus 4 times the amount of energy required to break a N—O double bond.
Subtract energy of bonds broken - energy of bonds formed and this is the change in enthalpy.
To know what type of bond it is, draw the Lewis structure.
When the enthalpy value is given, we can calculate how much heat is use or produces in a given equation.
67.6 kCal ---> 67.6 kCal= 1 mol of reaction
1 mol of reaction= 1 mol of CO (based on the coefficient)
so 1 mole of CO gives us 67.6 kCal of heat.
calculation:
1 mol CO
The answer for the following question is answered below.
- <em><u>Therefore the new pressure of the gas is 1.76 atm.</u></em>
Explanation:
Given:
Initial pressure of the gas = 1.34 atm
Initial temperature of the gas = 273 K
final temperature of the gas = 312 K
To solve:
Final temperature of the gas
We know;
From the ideal gas equation
P × V = n × R × T
So;
from the above equation we can say that
<em>P ∝ T</em>
= constant
=
Where;
= initial pressure of a gas
= final pressure of a gas
= initial temperature of a gas
= final temperature of a gas
=
= 1.76 atm
<em><u>Therefore the new pressure of the gas is 1.76 atm.</u></em>