Determine the amount of heat (in kJ) given off when 2.23 multiplied by 104 g of ammonia are produced according to the following equation. Assume that the reaction takes place under standard-state conditions at 25.0°C.
N2(g) + 3 H2(g) 2 NH3(g) ΔH°rxn = -92.6 kJ
How many moles NH3 do you have in 2.23 x 10^4 g NH3? So moles NH3 x 92.6 kJ/mol = ??
To determine the amount of heat given off when 2.23 x 10^4 g of ammonia are produced, we need to use the given equation and the molar mass of ammonia.
First, we need to calculate the number of moles of ammonia produced. To do this, we divide the given mass of ammonia by the molar mass of ammonia. The molar mass of ammonia (NH3) is calculated by adding up the atomic masses of each element in ammonia.
The atomic masses are as follows:
N = 14.01 g/mol
H = 1.01 g/mol
Therefore, the molar mass of ammonia (NH3) = (1.01 g/mol x 3) + 14.01 g/mol = 17.03 g/mol
Now, we can calculate the number of moles of ammonia produced:
Number of moles = mass of ammonia / molar mass of ammonia
Number of moles = 2.23 x 10^4 g / 17.03 g/mol
Next, we can use the balanced equation to determine the amount of heat released. The balanced equation gives us the stoichiometric relationship between the reactants (N2 and H2) and product (NH3), as well as the molar ratio.
From the balanced equation, we see that 1 mole of N2 reacts with 3 moles of H2 to produce 2 moles of NH3. Therefore, for every 2 moles of NH3 produced, the reaction releases -92.6 kJ of heat.
Finally, we calculate the amount of heat released for the given number of moles of ammonia produced:
Amount of heat released = Number of moles of ammonia x Heat of reaction per mole of ammonia
Amount of heat released = (Number of moles of ammonia x -92.6 kJ) / 2
Now you can plug in the value of the number of moles of ammonia from the previous step into the equation to find the amount of heat released.