Question

Given the coefficients of the balanced equation, the enthalpy of the reaction can be expressed in terms of the amount of ammonia as follows: ΔHrxn=−906 kJ4 mol NH3 Next, find the number of moles of NH3 that react to determine the heat associated with 345 g of NH3.

Answer 1

Answer:

q = -4588.89 kJ

Explanation:

First, we need to write the equation taht is taking place. In this case, is the combustion of NH3 so the reaction is as follow:

4NH3 + 5O2 --------> 4NO + 6H2O      ΔHrxn = -906 kJ

Now, in order to get the number of moles that react here and determine the heat, we first calculate the experimental moles of NH3 within the 345 g of ammonia:

moles = m/MM

The molar mass of NH3 is 17 g/mol so:

moles = 345 / 17 = 20.29 moles

Now, we will stablish a relation between the theorical moles and the experimental moles:

q = 20.29 moles * (-906) kJ / 4 moles

q = -4,588.89 kJ