Answer : The enthalpy change for the reaction is, 201.9 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 balanced reaction of will be,
The intermediate balanced chemical reaction will be,
(1)
(2)
(3)
(4)
Now we will multiply the reaction 1 by 2, revere the reaction 2, reverse and half the reaction 3 and 4 then adding all the equations, we get :
(1)
(2)
(3)
(4)
The expression for enthalpy of the reaction will be,
Therefore, the enthalpy change for the reaction is, 201.9 kJ
Explanation:
The acid involved is ethanoic acid which is
And the alkaline involved is calcium hydroxide which is
The equation for the reaction is
Hope this helps you
Here is a link to a website that explains these observed trends.
https://chem.libretexts.org/Bookshelves/Introductory_Chemistry/Book%3A_Introductory_Chemistry_(CK-12)/06%3A_The_Periodic_Table/6.15%3A_Periodic_Trends%3A_Atomic_Radius
Answer:
Period 4
Explanation:
Given the electronic configuration of the element;
= Is² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p¹
The period of the element is determined by the highest coefficient in the electronic configuration.
For this given configuration (Is² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p¹), "4" is the highest coefficient and the element will certainly belong to period 4 in the periodic table.
To test if the prediction is correct:
Total number of electrons in the given element = 2+2+6+2+6+10+2+1 = 31
The element with atomic number of 31 = Gallium (Ga). (This element belong to period 4).
Data Given:
% w/w = 5 %
Solution weight = 1500 g
Solute weight = ?
Formula Used:
% w/w = (Mass of Solute / Mass of Solution) × 100
Solving for Mass of Solute,
Mass of Solute = (% w/w × Mass of Solution) ÷ 100
Mass of Solute = (5 × 1500 g) ÷ 100
Mass of Solute = 75 g K₂SO₄