<u>Answer:</u> When the enthalpy of this overall chemical equation is calculated, the enthalpy of the second intermediate equation is halved and has its sign changed.
<u>Explanation:</u>
Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.
According to this law, the chemical equation is treated as ordinary algebraic expressions and can be added or subtracted to yield the required equation. This means that the enthalpy change of the overall reaction is equal to the sum of the enthalpy changes of the intermediate reactions.
The overall chemical reaction follows:

The intermediate balanced chemical reaction are:
(1)
(2)

The expression for enthalpy of the reaction follows:
![\Delta H^o_{rxn}=[1\times (\Delta H_1)]+[\frac{1}{2}\times (-\Delta H_2)]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5B1%5Ctimes%20%28%5CDelta%20H_1%29%5D%2B%5B%5Cfrac%7B1%7D%7B2%7D%5Ctimes%20%28-%5CDelta%20H_2%29%5D)
Hence, when the enthalpy of this overall chemical equation is calculated, the enthalpy of the second intermediate equation is halved and has its sign changed.
7=cells
9= The Central Nervous system
10= not sure
Before the development of electrophoresis to separate macromolecules, high-speed centrifugation was used to isolate DNA.
A laboratory procedure called electrophoresis is used to divide DNA, RNA, or protein molecules according to their size and electrical charge. The molecules are moved by an electric current through a gel or other matrix. The technology of electrophoresis is crucial for the separation and examination of nucleic acids. At the lab bench, cloned DNA fragments are frequently isolated and worked with using nucleic acid electrophoresis.
High-speed centrifugation employs centrifugal force to separate particles with various densities or masses suspended in a liquid. High-speed rotation of the solution inside the tube causes each particle's angular momentum to experience centrifugal forces inversely proportionate to its mass.
To know more about electrophoresis refer to: brainly.com/question/28709201
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The correct option is D.
The hydrogen atoms that are attached to the nitrogen atom in the ammonia molecule are capable of forming hydrogen bond. The hydrogen bond that exist in the ammonia molecule is the reason why it shows higher boiling point compare to the other hydrides. Hydrogen bond occur in ammonia because ammonia is one of the most electronegative elements.