The Haber process developed to produce fertilizer from nitrogen and hydrogen, is governed by the following unbalanced reaction:
a N2 + b H2 -> c NH3
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If 10.5 kg of NH3 product is required, how many kg of hydrogen are required if nitrogen is in excess?
so balance it. then you have the ratio of H2 to NH3 in moles, equal to b/c
all you have to do is convert 10kg of ammonia to moles.
To determine how many kilograms of hydrogen are required in the Haber process, we first need to balance the chemical equation. The given unbalanced equation is:
a N2 + b H2 -> c NH3
Since nitrogen is in excess, it means that it is not limiting the reaction. Therefore, we can assume that we have an unlimited supply of nitrogen.
To balance the equation, we need to ensure that the number of atoms of each element is the same on both sides of the equation. Let's balance the equation step by step:
First, let's balance the nitrogen (N) atoms. There are two nitrogen atoms on the left side (N2), so we need two on the right side as well. Therefore, we have:
a N2 + b H2 -> 2 NH3
Next, let's balance the hydrogen (H) atoms. There are 2b hydrogen atoms on the right side (2 NH3), so we need 2b hydrogen atoms on the left side. Therefore, we have:
a N2 + 2b H2 -> 2 NH3
Now that we have balanced the nitrogen and hydrogen atoms, we can see that the coefficients a, b, and c represent the stoichiometric ratios between the reactants and products.
Since we are looking for the number of kilograms of hydrogen required, we need to determine the stoichiometric ratio for hydrogen. From the balanced equation, we can see that 2b moles of hydrogen react to produce 2 moles of ammonia (NH3). Therefore, the stoichiometric ratio of hydrogen to ammonia is (2b H2)/(2 NH3), which simplifies to b/(1 NH3).
To find the value of b, we need the molar mass of ammonia (NH3) and the desired quantity of ammonia to be produced:
Molar mass of NH3 = 14.01 g/mol (N) + 3 * 1.01 g/mol (H) = 17.03 g/mol
We have 10.5 kg of NH3:
10.5 kg * 1000 g/kg = 10500 g
Now, we can calculate the number of moles of ammonia produced:
moles of NH3 = mass / molar mass = 10500 g / 17.03 g/mol
Finally, to find the number of moles of hydrogen required (b), we multiply the moles of ammonia produced by the stoichiometric ratio of hydrogen to ammonia:
moles of H2 = moles of NH3 * (b/1 NH3)
Therefore, to determine the number of kilograms of hydrogen required, we need to convert the moles to kilograms:
mass of H2 = moles of H2 * molar mass of H2
And that's how you can calculate the number of kilograms of hydrogen required in the Haber process.