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
Ba(OH)₂(aq) + 2HNO₃(aq) = Ba(NO₃)₂(aq) + 2H₂O(l)
At the reaction of barium hydroxide with nitric acid there are no visual changes.
Ba(OH)₂(aq) + H₂SO₄(aq) = BaSO₄(s) + 2H₂O
At the reaction of barium hydroxide with sulfuric acid the precipitat of white color is formed.
Answer:
Diagram 1
Explanation:
The solubility of the oxygen gas in water has to do with the interaction of the oxygen with the dipoles in water.
Water is a polar molecule having oxygen as the negative dipole and hydrogen as the positive dipole.
Water can interact with the oxygen atoms in the molecule via intermolecular hydrogen bonds with molecular oxygen as shown in diagram 1.
Answer:
During ice ages, the most characteristic change to the planet has been the formation and spread large ice sheets and glaciers across much the Northern Hemisphere.