Answer: The change in enthalpy will be -13.
Explanation:-
Endothermic reactions absorb heat, while exothermic reactions release heat. In the case of an endothermic reaction, the change in enthalpy is represented as positive, whereas for an exothermic reaction, it is negative.
When one mole of A combines with one mole of B to form three moles of C
So the stoichiometric ratio being halved also results in the enthalpy for the reaction being halved.
Question 1.
The accurate statement is " Aluminium, as it belongs to group 13 and contains three valence electrons. The Lewis dot structure illustrates the number of valence electrons in a single atom. By referencing the periodic table, we identify the element based on its valence electrons. Indeed, aluminium possesses 3 valence electrons and is located in Group 13 of the periodic table.
Question 2.
The correct count is 5. The outer layer of electrons is termed the valence shell, containing what we refer to as valence electrons. Here, the outermost shell corresponds to n=3, meaning all electrons in this layer are classified as valence electrons. While we do have subshells (3s and 3p), they indicate the spatial region where an electron may be located but do not clarify valence.
Question 3.
Chlorine possesses 7 valence electrons, Neon has 8 valence electrons, Phosphorus contains 5 valence electrons, Sulfur has 6 valence electrons. The position of an element in the periodic table aids in determining its electron configuration, and the group number provides insights into the number of valence electrons. By merely checking the periodic table's group number, we can ascertain the valence electrons.
Question 4.
The assertion is True. As atomic orbitals fill, the energy levels extend farther from the nucleus. The outermost orbital capable of being filled with electrons is known as the valence shell, and the electrons within are termed valence electrons. This characteristic defines the reactivity of particular elements.
Question 5.
The atom with the electron configuration contains an unpaired electron in its 3s orbital, rendering it unstable. Meanwhile, the element with 7 valence electrons requires just one additional electron to complete its octet. Therefore, the
atom loses an electron to bond with the element holding 7 valence electrons. Consequently, the element
acquires a positive charge, while the one with 7 valence electrons becomes negatively charged, leading to the formation of an ionic bond.