Answer: The correct answer is -297 kJ.
Explanation:
To solve this problem, we want to modify each of the equations given to get the equation at the bottom of the photo. To do this, we realize that we need SO2 on the right side of the equation (as a product). This lets us know that we must reverse the first equation. This gives us:
2SO3 —> O2 + 2SO2 (196 kJ)
Remember that we take the opposite of the enthalpy change (reverse the sign) when we reverse the equation.
Now, both equations have double the coefficients that we would like (for example, there is 2S in the second equation when we need only S). This means we should multiply each equation (and their enthalpy changes) by 1/2. This gives us:
SO3 —>1/2O2 + SO2 (98 kJ)
S + 3/2O2 —> SO3 (-395 kJ)
Now, we add the two equations together. Notice that the SO3 in the reactants in the first equation and the SO3 in the products of the second equation cancel. Also note that O2 is present on both sides of the equation, so we must subtract 3/2 - 1/2, giving us a net 1O2 on the left side of the equation.
S + O2 —> SO2
Now, we must add the enthalpies together to get our final answer.
-395 kJ + 98 kJ = -297 kJ
Hope this helps!
Answer:
E
Explanation:
Here in this question, what we will do is to select which of the pairs that do not correlate.
A. Enthalpy and heat content
This two terms are at par with each other. By definition, the enthalpy of a system simply is the total amount of heat content it has.
B. Endothermic reaction and +H
These two terms are at par with each other. An endothermic reaction is one in which heat is absorbed from the surroundings. It has a positive value for the heat content i.e the enthalpy is positive and thus H is positive.
C. Exothermic reaction and -H
An exothermic reaction is one in which heat is released to the environment. It usually has a negative value for the enthalpy and thus the value of H is negative.
D. High energy and High Stability
These two terms are not at par. When an entity has or is of high energy, it is usually unstable. An entity at a higher energy level will not be stable until it goes to a lower level of energy.
Thus higher energy level is associated with lesser stability while lower energy levels are associated with higher stability. The lesser the energy of an entity, the higher its stability.
This makes the option our answer.
Answer : The equilibrium concentration of 
in the trial solution is 
Explanation :
First we have to calculate the initial moles of 
and .
and,
The given balanced chemical reaction is,
Since 1 mole of reacts with 1 mole of to give 1 mole of 
The limiting reagent is,
So, the number of moles of = 0.0020 mmole
Now we have to calculate the concentration of .
Using Beer-Lambert's law :
where,
A = absorbance of solution
C = concentration of solution
l = path length
= molar absorptivity coefficient
and l are same for stock solution and dilute solution. So,
For trial solution:
The equilibrium concentration of is,
![[SCN^-]_{eqm}=[SCN^-]_{initial}-[FeSCN^{2+}]](https://tex.z-dn.net/?f=%5BSCN%5E-%5D_%7Beqm%7D%3D%5BSCN%5E-%5D_%7Binitial%7D-%5BFeSCN%5E%7B2%2B%7D%5D)
![[SCN^-]_{initial}](https://tex.z-dn.net/?f=%5BSCN%5E-%5D_%7Binitial%7D)
= 0.00050 M
Now calculate the ![[FeSCN^{2+}]](https://tex.z-dn.net/?f=%5BFeSCN%5E%7B2%2B%7D%5D)
.
Now calculate the concentration of .
![[SCN^-]_{eqm}=(0.00050M)-(9.17\times 10^{-5}M)](https://tex.z-dn.net/?f=%5BSCN%5E-%5D_%7Beqm%7D%3D%280.00050M%29-%289.17%5Ctimes%2010%5E%7B-5%7DM%29)
![[SCN^-]_{eqm}=4.58\times 10^{-8}M](https://tex.z-dn.net/?f=%5BSCN%5E-%5D_%7Beqm%7D%3D4.58%5Ctimes%2010%5E%7B-8%7DM)
Therefore, the equilibrium concentration of in the trial solution is
Answer:
This is all true if the atom has to be neutral.
Also what does V mean?
Helium: one shell with 2 neutrons and 2 protons in the center, with 2 electrons in the first shell.
Lithium: two shells with 4 neutrons and 3 protons in the center, with 2 electrons in the first shell, and 1 electron in the second shell.
Nitrogen: two shells with 7 neutrons and 7 protons in the center, with 2 electrons in the first shell, and 5 electrons in the second shell.
Flourine: two shells with 9 protons and 10 neutrons in the center, with 2 electrons in the first shell, and 7 electrons in the second shell.
Neon: two shells with 10 neutrons and 10 protons in the center, with 2 electrons in the first shell, and 8 electrons in the second shell.
Boron: two shells with 6 neutrons and 5 protons in the center, with 2 electrons in the first shell, and 3 electrons in the second shell.
Answer: Electrovalent bonds are produced when electrons are transferred from atoms of one element to atoms of another element, producing positive and negative ions. The bond which is formed by the transfer of electrons between the atoms is called electrovalent bond or ionic bond. Electrovalent bonds are only formed between metals and non-metals. Electrovalent bonds are not formed between two non-metals.
In simple words electrovalent bond involves the transference of a certain number of electrons to another dissimilar atom which has a tendency to gain electrons so that both acquire stable inert gas configurations. The electrostatic attraction always tends to decrease the potential energy. Hence, the potential energy of the system is much less than it was before the formation of an ionic bond.
Explanation: An Ionic bond is the bond formed by the complete transfer of valence electron to attain stability.
This type of bonding leads to the formation of two oppositely charged ions – positive ion known as cations and negative ions are known as anions.
The presence of two oppositely charged ions results in a strong attractive force between them. This force is an ionic or electrovalent bond.
Ionic bonds form between atoms with large differences in electronegativity, whereas covalent bonds formed between atoms with smaller differences in electronegativity.
The compound formed by the electrostatic attraction of positive and negative ions is called an ionic compound.
