Answer: 250 kJ
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 Hess’s law, the chemical equation can be treated as algebraic expressions 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)
(2)
Net chemical equation:
(3)
Adding 1 and 2 we get,
(4)
Now dividing equation (4) by 4, we get
(4)
Answer:
If your asking why they are different because atoms are rearranged in a chemical reaction, there must be the same number of sodium atoms and chlorine atoms in both reactants and products for them to be the same.
Answer:
The oxidation number of an atom is the charge it appears to have when you count the electrons according to some arbitrary rules. The oxidation number of an atom depends on the other atoms in the substance.
Explanation:
For example, In KCl, the oxidation number of Cl is 0.