Answer : The enthalpy change of reaction is -1800 kJ
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The given final reaction is,

The intermediate balanced chemical reaction will be,
(1)

(2)

First we will multiply reaction 1 by 2 and reverse reaction of reaction 2 by 3 then adding both the equation, we get :
The expression for final enthalpy is,
![\Delta H=[n\times \Delta H_1]+[n\times (-\Delta H_2)]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5Bn%5Ctimes%20%5CDelta%20H_1%5D%2B%5Bn%5Ctimes%20%28-%5CDelta%20H_2%29%5D)
where,
n = number of moles
![\Delta H=[2mole\times (-1680kJ/mole)]+[3\times -(-520kJ/mole)]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B2mole%5Ctimes%20%28-1680kJ%2Fmole%29%5D%2B%5B3%5Ctimes%20-%28-520kJ%2Fmole%29%5D)

Therefore, the enthalpy change of reaction is -1800 kJ
Question: What is shown on the photo above?
Choices: A) An aquifer B) A sinkhole C) A watershed D) Karst topography
Answer: <u>It's C) A watershed because A. is where the water is underground, B. is a sinkhole and it has a big hole that is big or sometimes small, and D. Is where it has a little crack in it and it goes underground. </u>
<em>Hope this helps!.</em>
<em>~~~~~~~~~~~~~~~~~~~</em>
<em>~A.W~ZoomZoom44</em>
Answer:
There are exactly 5
Explanation:
IF YOU BREAK IT UP IT WILL BE FIVE
Hormones which are chemical produced in the body.The hormones are like chemical messages which send a message to the ovaries.the ovaries release hormones which work together hence starting puberty
Answer:
Molecules move freely around since they don't have a definite shape. This is the reason water stays liquid and couldn't be gripped.