Answer:
-196 kJ
Explanation:
By the Hess' Law, the enthalpy of a global reaction is the sum of the enthalpies of the steps reactions. If the reaction is multiplied by a constant, the value of the enthalpy must be multiplied by the same constant, and if the reaction is inverted, the signal of the enthalpy must be inverted too.
2S(s) + 3O₂(g) → 2SO₃(g) ΔH = -790 kJ
S(s) + O₂(g) → SO₂(g) ΔH = -297 kJ (inverted and multiplied by 2)
2S(s) + 3O₂(g) → 2SO₃(g) ΔH = -790 kJ
2SO₂(g) → 2S(s) + 2O₂(g) ΔH = +594 kJ
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2S(s) + 3O₂(g) + 2SO₂(g) → 2SO₃(g) + 2S(s) + 2O₂(g)
Simplifing the compounds that are in both sides (bolded):
2SO₂(g) + O₂(g) → 2SO₃(g) ΔH = -790 + 594 = -196 kJ
This hypothesis can be further substantiated by having different concentrations of acid and the same mass of limestone.
<h3>Rate of reaction</h3>
Though the question is incomplete, we must try to answer it the much we can. Recall that a hypothesis is a tentative explanation for an observation which is subject to empirical verification.
We know that the rate of reaction depends on the concentration of the acid. This hypothesis can be further substantiated by having different concentrations of acid and the same mass of limestone.
Learn more about rate of reaction: brainly.com/question/8592296
It’s definitely magnesium but it may not be
Answer:
3
Explanation:
The first election shell can only hold 2 electrons, but the next one can hold up to 8