<u>Answer:</u> The
for the reaction is -1835 kJ.
<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 given chemical reaction follows:

The intermediate balanced chemical reaction are:
(1)
( × 4)
(2)

The expression for enthalpy of the reaction follows:
![\Delta H^o_{rxn}=[4\times (-\Delta H_1)]+[1\times \Delta H_2]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5B4%5Ctimes%20%28-%5CDelta%20H_1%29%5D%2B%5B1%5Ctimes%20%5CDelta%20H_2%5D)
Putting values in above equation, we get:

Hence, the
for the reaction is -1835 kJ.
C. single replacement. A single replacement is represented by this formula : AB + C = AC + B
Answer:
When atoms are excited they emit light of certain wavelengths which correspond to different colors. Each element produces a unique set of spectral lines. Since no two elements emit the same spectral lines, elements can be identified by their line spectrum.
Explanation:
The rule that we will use to solve this problem is:
M2*V1 = M2*V2 where:
M1 is the initial concentration = 3.5 m
V1 is the initial volume = 0.25 l = 250 ml
M2 is the final concentration = 9 m
V2 is the final volume that we need to find
Substitute with the givens in the above equation to get V2 as follows:
3.5*250 = 9*V2
V2 = 97.2223 ml