(a) In an equilibrium reaction between gases Q and R, to form QR, the energy content of the reactants is 100 KJ and that of the product is 54 kJ. The energy...

(a) In an equilibrium reaction between gases Q and R, to form QR, the energy content of the reactants is 100 KJ and  that of the product is 54 kJ. The energy content of the activated complex is 210 KJ.

(i) Draw an energy profile diagram for the reaction. (ii) Determine the: I. activation energy of the reaction il. enthalpy change ΔH of the reaction. (iii) Write a balanced equation for the reaction. (iv) Give a reason for the answer given in 3(C)(iv). (iv) State whether the  reaction is exothermic or endothermic.

(b) Consider the following table:

(i) Write the electron configuration for each of the elements. Element E, F, G, H 12 13 (ii) State: I. two elements that are metals; II. the elements(s) most likely to form an ion with a charge of +3; III. the element(s) which belong(s) to group VII. on the periodic table; IV. the formula of the compound formed between F and G. Atomic 

(c) Define the term isotopy  (d) Name the three building blocks of matter.

Answer Details

(a)(i) An energy profile diagram can be drawn as follows:

Reactants (100 kJ) ----> Activated complex (210 kJ) ----> Products (54 kJ)

(a)(ii)
I. The activation energy of the reaction can be calculated as the difference in energy between the activated complex and the reactants, which is 210 kJ - 100 kJ = 110 kJ.
II. The enthalpy change, ΔH, of the reaction can be calculated as the difference in energy between the products and the reactants, which is 100 kJ - 54 kJ = 46 kJ.

(a)(iii) The balanced equation for the reaction cannot be determined with the information given.

(a)(iv) The reason for not being able to determine the balanced equation is because the information about the chemical formulas of the reactants, products, and the coefficients in the balanced equation are missing.

(a)(v) Based on the enthalpy change of the reaction, ΔH = 46 kJ, the reaction is exothermic.

(b)(i) The electron configuration for the elements can be determined as follows:

Element E: 1s² 2s² 2p³
Element F: 1s² 2s² 2p⁵
Element G: 1s² 2s² 2p⁶ 3s² 3p⁶
Element H: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹

(b)(ii)
I. The elements that are metals are element E and G.
II. The element most likely to form an ion with a charge of +3 is element H.
III. Element H belongs to group VII on the periodic table.
IV. The formula of the compound formed between F and G can be determined by combining the elements in a ratio that results in a neutral compound. Given that F has 9 electrons and G has 12 electrons, the formula of the compound can be determined as FG₂, or FG, with a charge of 2-.

(c) Isotopy refers to the existence of isotopes, which are atoms of the same element that have the same number of protons but a different number of neutrons in their nucleus.

(d) The three building blocks of matter are protons, neutrons, and electrons. Protons and neutrons make up the nucleus of an atom and are made up of even smaller particles called quarks. Electrons orbit the nucleus and are much lighter than the protons and neutrons. These three particles make up all matter in the universe and determine the chemical and physical properties of the elements.