Determine the amount of heat (in kJ) given off when 2.07 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
You didn't write an arrow. Without an arrow we can't tell the difference between the products and the reactants. I will place the arrow where I think it goes but you correct me if I'm wrong.
N2(g) + 3H2(g) ==>2NH3(g)
So 92.6 kJ of heat are produced to form how many grams of NH3? Would that be 2 x molar mass = 2 x 17 = 34 g NH3?
Then 92.6 kJ x (2.07 x 10^4/34) = ??
Check my thinking. Check my typing.
Yes you had the equation right. And that worked.
Thank you!
To determine the amount of heat given off when 2.07 x 10^4 g of ammonia (NH3) are produced, we need to use the given balanced equation and the enthalpy change (ΔH°rxn).
The balanced equation is:
N2(g) + 3 H2(g) -> 2 NH3(g)
The enthalpy change is ΔH°rxn = -92.6 kJ.
Step 1: Calculate the molar mass of ammonia (NH3).
The molar mass of NH3 = 1(14.01 g/mol) + 3(1.01 g/mol) = 17.04 g/mol.
Step 2: Convert the given mass of ammonia to moles.
moles of NH3 = (mass of NH3) / (molar mass of NH3)
moles of NH3 = (2.07 x 10^4 g) / (17.04 g/mol) = 1213.2 mol
Step 3: Determine the amount of heat evolved using the stoichiometry of the balanced equation.
From the balanced equation, we can see that the stoichiometric coefficient of NH3 is 2. Therefore, 2 moles of NH3 produce -92.6 kJ of heat.
moles of NH3 produced = 2 * (moles of N2)
moles of N2 = moles of NH3 / 2 = 1213.2 mol / 2 = 606.6 mol
The heat released can be calculated using the stoichiometric ratio and the given enthalpy change:
Heat released = (moles of N2) * (-92.6 kJ/mol)
Heat released = 606.6 mol * (-92.6 kJ/mol)
Step 4: Calculate the total amount of heat in kJ.
Heat released = -56230.16 kJ (rounded to the nearest hundredth)
Therefore, the amount of heat given off when 2.07 x 10^4 g of ammonia are produced is approximately -56230.16 kJ. Note that the negative sign indicates that the reaction is exothermic, meaning heat is released.
To determine the amount of heat given off when 2.07 × 10^4 g of ammonia are produced according to the given equation, we need to use the stoichiometry of the reaction and the enthalpy change of the reaction.
First, let's calculate the number of moles of ammonia produced:
- Convert grams of ammonia to moles using its molar mass. The molar mass of ammonia (NH3) is 17.031 g/mol.
Moles of ammonia = Mass of ammonia / Molar mass of ammonia
= 2.07 × 10^4 g / 17.031 g/mol
Next, we can determine the amount of heat released using the stoichiometry of the balanced reaction equation. According to the balanced equation, 2 moles of ammonia are produced for every 1 mole of N2 and 3 moles of H2.
- Divide the moles of ammonia by the stoichiometric coefficient of ammonia (2) to find the moles of N2 and H2 required.
- Multiply the moles of N2 and H2 by the molar enthalpy change (ΔH°rxn) to determine the heat released.
Heat released = (Moles of N2 + Moles of H2) × ΔH°rxn
Finally, convert the heat released from J to kJ by dividing by 1000.
Given the information, you can now follow these steps to calculate the amount of heat released.