Answer:
ΔU=-369.2 kJ/mol.
Explanation:
We start from the equation:
Δ(H)=ΔU+Δ(PV), which is an extension of the well known relation: H=U+PV.
If Δ(PV) were calculated by ideal gas law,
PV=nRT
Δ(PV)=RTΔn.
Where Δn is the change of moles due to the reaction; but, this reaction does not give a moles change (Four moles of HCl produced from 4 moles of reactants), so Δ(PV)=0.
So, for this case, ΔH=ΔU.
The enthalpy of reaction given is for one mole of reactant, so the enthalpy of reaction for the reaction of interest must be multiplied by two:
ΔU=-369.2 kJ/mol.
Thee question is incomplete; the complete question is;
Which elements do not strictly follow the octet rule when they appear in the Lewis structure of a molecule?
Select one or more:
A: Chlorine
B: Carbon
C: Hydrogen
D: Sulfur
E: Fluorine
F: Oxygen
Answer:
chlorine
sulphur
Explanation:
The octet rule states that, for atoms to be stable, they must have eight electrons on their outermost shells.
This rule is not strictly followed by some elements such as sulphur and chlorine. The atoms of these elements can sometimes expand their octet by utilizing the d-orbitals found in the third principal energy level and beyond.
These leads to formation of compounds in which the central atom has more than eight electrons in its outermost shell.
When solid aluminum metal is reacted with diatomic chlorine gas, solid aluminum chloride is formed. This reaction is an example of synthesis or chemical combination in which two elements, aluminum and chlorine combine to form a new compound aluminum chloride.
Word equation: Aluminum (s)+ Chlorine (g)---> Aluminum chloride(s)
Molecular formula of the product formed is 
.
Therefore the balanced chemical equation representing the reaction of solid aluminum with gaseous dichlorine can be represented as,
Answer:
The answer is: A
Explanation:
The wave-like contractions are to be considered a physical change as they do not take part in the breaking-down of the food. The peptidase is a chemical change because it is used to chemically break down the food to retrieve nutrients and such.
Answer:
In the calorimeter, water is the <u>exothermic</u>. The salt LiCI, which will dissolve, is the <u>endothermic</u>. The final temperature of the water after the dissolution of LiCI was <u>lower</u> than the initial temperature, meaning the process is <u>exothermic</u>. In the microscopic view of the disspolution of LiCI, water molecules were seen to move <u>slowly</u> as they <u>gained </u>energy.
Explanation:
Exothermic is a process in which heat is released during the process. Endothermic reactions absorbs heat from surrounding during a chemical process. The dissolution of salt into water is an exothermic reaction. During this process heat is release and water molecules are broken down which are surrounded by salt ions.
