Answer:
![\Delta\text{H}_1+2\Delta\text{H}_2-\Delta\text{H}_3](https://tex.z-dn.net/?f=%5CDelta%5Ctext%7BH%7D_1%2B2%5CDelta%5Ctext%7BH%7D_2-%5CDelta%5Ctext%7BH%7D_3)
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
A. Radiation
Air in a car is heated up with the radiator and then blown out with an air pump.
Answer:
Option D) Compound B may have a lower molecular weight.
Explanation:
Compound A and B are standing at the same temperature yet compound A is evaporating more slowly than compound B.
This simply indicates that compound B have a lower molecular weight than compound A.
This can further be seen when gasoline and kerosene are placed under same temperature. The gasoline will evaporate faster than kerosene because the molecular weight of the gasoline is low when compared to that of the kerosene.
Answer:
![\large \boxed{\text{41.2 cm}^{3}}](https://tex.z-dn.net/?f=%5Clarge%20%5Cboxed%7B%5Ctext%7B41.2%20cm%7D%5E%7B3%7D%7D)
Explanation:
1. Mass of zinc
The density of zinc is 7.14 g/cm³
D = m/V
![\begin{array}{rcl}7.14 & = & \dfrac{m}{15.0}\\\\m & = & 7.14 \times 15.0\\& = & \text{107.1 g}\\\end{array}\\](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Brcl%7D7.14%20%26%20%3D%20%26%20%5Cdfrac%7Bm%7D%7B15.0%7D%5C%5C%5C%5Cm%20%26%20%3D%20%26%207.14%20%5Ctimes%2015.0%5C%5C%26%20%3D%20%26%20%5Ctext%7B107.1%20g%7D%5C%5C%5Cend%7Barray%7D%5C%5C)
2. Volume of aluminium
The density of aluminium is 2.60/cm³.
![\begin{array}{rcl}2.60 & = & \dfrac{107.1}{V}\\\\2.60V & = & 107.1\\V& = &\dfrac{107.1}{2.60}\\\\& = &\textbf{41.2cm}^{\mathbf{3}}\\\end{array}\\\large \boxed{\textbf{41.2 cm}^{\mathbf{3}}}\text{ of aluminium have the same mass as 15.0 cm$^{3}$ of zinc.}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Brcl%7D2.60%20%26%20%3D%20%26%20%5Cdfrac%7B107.1%7D%7BV%7D%5C%5C%5C%5C2.60V%20%26%20%3D%20%26%20107.1%5C%5CV%26%20%3D%20%26%5Cdfrac%7B107.1%7D%7B2.60%7D%5C%5C%5C%5C%26%20%3D%20%26%5Ctextbf%7B41.2cm%7D%5E%7B%5Cmathbf%7B3%7D%7D%5C%5C%5Cend%7Barray%7D%5C%5C%5Clarge%20%5Cboxed%7B%5Ctextbf%7B41.2%20cm%7D%5E%7B%5Cmathbf%7B3%7D%7D%7D%5Ctext%7B%20of%20aluminium%20have%20the%20same%20mass%20as%2015.0%20cm%24%5E%7B3%7D%24%20of%20zinc.%7D)