HELPPP The sum of percentage compositions must equal to 100 ±0.1. True False
2 answers:
You might be interested in
Answer : The enthalpy change of reaction is -1800 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 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.
The given final reaction is,
The intermediate balanced chemical reaction will be,
(1)
(2)
First we will multiply reaction 1 by 2 and reverse reaction of reaction 2 by 3 then adding both the equation, we get :
The expression for final enthalpy is,
where,
n = number of moles
Therefore, the enthalpy change of reaction is -1800 kJ
Explanation:
Relation between entropy change and specific heat is as follows.
The given data is as follows.
mass = 500 g, = 24.4 J/mol K
= 500 K,
= 250 K
Mass number of copper = 63.54 g /mol
Number of moles =
=
= 7.86 moles
Now, equating the entropy change for both the substances as follows.
=
= 750
So, =
- For the metal block A, change in entropy is as follows.
=
= -3.04 J/ K mol
- For the block B, change in entropy is as follows.
=
= 4.296 J/Kmol
And, total entropy change will be as follows.
= 4.296 + (-3.04)
= 1.256 J/Kmol
Thus, we can conclude that change in entropy of block A is -3.04 J/ K mol and change in entropy of block B is 4.296 J/Kmol.