I believe that the best answer among the choices provided by the question is <span>It is the difference between reactant energy and maximum energy.
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Answer:

Explanation:
Hello,
In this case, we write the reaction again:

In such a way, the first thing we do is to compute the reacting moles of lead (II) nitrate and potassium iodide, by using the concentration, volumes, densities and molar masses, 331.2 g/mol and 166.0 g/mol respectively:

Next, as lead (II) nitrate and potassium iodide are in a 1:2 molar ratio, 0.04635 mol of lead (II) nitrate will completely react with the following moles of potassium nitrate:

But we only have 0.07885 moles, for that reason KI is the limiting reactant, so we compute the yielded grams of lead (II) iodide, whose molar mass is 461.01 g/mol, by using their 2:1 molar ratio:

Best regards.
When reversing a given reaction, we simply change the sign of the standard enthalpy change value. Therefore, the reaction will become:
H₂O → H₂ + 0.5O₂, ΔH = 286kJ
This is because if a certain amount of energy is released when a reaction occurs, the same amount of energy must be supplied for the reaction to occur in the reverse direction.
Explanation:
Given parameters:
Number of moles of the sulfur trioxide = 1.55kmol = 1.55 x 10³mole
Unknown:
Mass of the sulfur trioxide = ?
Solution:
To solve for the mass of the sample of sulfur trioxide:
- Find the molar mass of the compound i.e SO₃
atomic mass of S = 32g
O = 16g
molar mass = 32 + 3(16) = 80g/mol
mass of SO₃ = number of moles x molar mass
mass of SO₃ = 1.55 x 10³ x 80 = 124000g or 124kg
Learn more:
mole calculation brainly.com/question/13064292
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