Answer:

Explanation:
Hess's Law of Constant Heat Summation states that if a chemical equation can be written as the sum of several other chemical equations, the enthalpy change of the first chemical equation is equal to the sum of the enthalpy changes of the other chemical equations. Thus, the reaction that involves the conversion of reactant A to B, for example, has the same enthalpy change even if you convert A to C, before converting it to B. Regardless of how many steps it takes for the reactant to be converted to the product, the enthalpy change of the overall reaction is constant.
With Hess's Law in mind, let's see how A can be converted to 2C +E.
(Δ
) -----(1)
Since we have 2B, multiply the whole of II. by 2:
(2Δ
) -----(2)
This step converts all the B intermediates to 2C +2D. This means that the overall reaction at this stage is
.
Reversing III. gives us a negative enthalpy change as such:
(-Δ
) -----(3)
This step converts all the D intermediates formed from step (2) to E. This results in the overall equation of
, which is also the equation of interest.
Adding all three together:
(
)
Thus, the first option is the correct answer.
Supplementary:
To learn more about Hess's Law, do check out: brainly.com/question/26491956
Answer:
C
Explanation:
Potassium metal reacts very rapidly with water, which forms Potassium hydroxide (KOH) and hydrogen gas (H2).
I need the answer choices plz :)
Since Oxygen is in group 16, this element has 6 valence electrons. Valence electrons like to become as stable as possible and similar to a noble gas, which has 8 electrons. You need to find an element that will transfer its atoms to the oxygen to make 8 electrons. Looking at the periodic table, Selenium is in group 16 and will have 6 valence electrons (6 + 6 = 12). This can't transfer electrons with Oxygen. Hydrogen is in group 1 with 1 valence electron (6 + 1 = 7). This can't transfer electrons with Oxygen. Strontium is in group 2 with 2 valence electrons (6 + 2 = 8). This will transfer electrons to Oxygen, making it the most stable.
The answer is O and Sr.