A substance that undergoes change during a reaction, usually from coming in contact with another substance
Electron affinity is the change in energy of an atom with a neutral charge when an electron is added to form an anion. A more negative electron affinity corresponds to a greater attraction for an electron. Electron affinity become less negative down a group and from left to right in the periodic table.
Answer:
The reaction is:
H⁺
CaCO₃ ⇄ Ca²⁺ + CO₃ ⇄ HCO₃
The standard free energy change is ΔG = ΔH - TΔS
Explanation:
Limestone is a mineral familiar with calcium carbonate, and being very common, the acid present in acid rain dissolves it reacting with carbonate, since the acids present in acid rain are characterized by being highly soluble in water and are also strong acids. The reaction is as follows:
H⁺
CaCO₃ ⇄ Ca²⁺ + CO₃ ⇄ HCO₃
The spontaneity of the reaction is equal to:
ΔG = ΔH - TΔS
The sign of the standard free energy changes from positive to negative.
The relationship between the evaporation rate and the likelihood that the liquid will be flammable is its flash point number (or the lowest temperature for which the liquid ignites) and its activation energy (how much energy is required to ignite it). With volatile liquids or gases these numbers seem to be lower.
Answer: 
.
Explanation:
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
(1)
![S_{monoclinic}+O_2(g)\rightarrow SO_2(g)/tex] [tex]\Delta H^0_2=-296.36kJ](https://tex.z-dn.net/?f=S_%7Bmonoclinic%7D%2BO_2%28g%29%5Crightarrow%20SO_2%28g%29%2Ftex%5D%20%5Btex%5D%5CDelta%20H%5E0_2%3D-296.36kJ)
(2)
The final reaction is:
(3)
By subtracting (1) and (2)
Hence the enthalpy change for the transformation S(rhombic) → S(monoclinic) is 0.3kJ
