Answer:
-767,2kJ
Explanation:
It is possible to sum enthalpies of half-reactions to obtain the enthalpy of a global reaction using Hess's law. For the reactions:
1) H₂(g) + ¹/₂O₂(g) ⟶ H₂O(g) ΔH₁= −241.8 kJ
2) X(s) + 2Cl₂(g) ⟶ XCl₄(s) ΔH₂= +361.7 kJ
3) ¹/₂H₂(g) + ¹/₂Cl₂(g) ⟶ HCl (g) ΔH₃= −92.3 kJ
4) X(s) + O₂(g) ⟶ XO₂(s) ΔH₄= − 607.9 kJ
5) H₂O(g) ⟶ H₂O(l) ΔH₅= − 44.0 kJ
The sum of (4) - (2) produce:
6) XCl₄(s) + O₂(g) ⟶ XO₂(s) + 2Cl₂(g) ΔH₆ = ΔH₄ - ΔH₂ = -969,6 kJ
(6) + 4×(3):
7) XCl₄(s) + 2H₂(g) + O₂(g) ⟶ XO₂(s) + 4HCl(g) ΔH₇ = ΔH₆ + 4ΔH₃= -1338,8 kJ
(7) - 2×(1):
8) XCl₄(s) + 2H₂O(g) ⟶ XO₂(s) + 4HCl(g) ΔH₈ = ΔH₇ - 2ΔH₁= -855,2kJ
(8) - 2×(5):
9) XCl₄(s) + 2H₂O(l) ⟶ XO₂(s) + 4HCl(g) ΔH₉ = ΔH₈ - 2ΔH₅= <em>-767,2kJ</em>
I hope it helps!
Answer:
One nucleophilic center
Explanation;
Nucleophile:
Nucleophile is a substance which is nucleus loving in nature (<em>Nucleo</em>; Nucleus , <em>phile</em>; Loving). It is known as a specie which donates a lone pair of electrons to electrophile (electron loving) in a chemical reaction.
Thus, Nucleophile is the region of higher electron density in a molecule and attacks on the lower electron density region of another molecule. Also, the nucleophile can also contain a negative charge.
Number of Nucleophilic centers in Methanol:
The chemical structure of Methanol is attached below and it can be observed that the oxygen atom is containing two lone pair of electrons. Hence, the oxygen atom can act as a nucleophilic center. Therefore, there is only one nucleophilic center in methanol.
H₃C-OH + H₃C-Br → H₃C-O-CH₃ + HBr
In above reaction methanol is acting as a nucleophile and is attacking on electrophilic center (Carbon) of methyl bromide yielding dimethyl ether.
Answer:
Mud was deposited first, then sand.
Explanation:
This could have been a tidal mud flat succeeded by a sandy beach, or along the bed and course of a river with either mountain building upstream causing faster flow and carrying of mud farther away or the sea level falling with mud deposits being found closer to the new coastline. Hope this helps!
C. marbles placed inside hollow sphere
At divergent boundaries, plates separate, forming a narrow rift valley. Here, geysers spurt super-heated water, and magma, or molten rock, rises from the mantle and solidifies into basalt, forming new crust. Thus, at divergent boundaries, oceanic crust is created.
