To determine the atomic number of the atom X in the equation \( X + 2e^- \rightarrow X^{2-} \), we need to understand what this equation represents. The equation shows that the neutral atom X is gaining 2 electrons to form the X2- ion. This implies that X initially has two fewer electrons than X2-.
The atomic number of an element equals the number of protons in a neutral atom of that element. Since the elemental state of X is neutral, the number of electrons must match the number of protons (i.e., the atomic number).
Thus, the correct answer to the question, "The atomic number of the atom X is:" is 16.
To confirm, consider the periodic table where sulfur (S) has an atomic number of 16, which commonly forms a sulfide ion \( S^{2-} \) by gaining two electrons, aligning with the process described in the equation.
Bauxite is the principal ore used in the commercial extraction of aluminium. The Bayer’s process is used to refine bauxite into pure alumina, with caustic soda playing a crucial role in the initial stage of the process. Based on this, answer the following questions:
(a) Explain the reason behind the addition of caustic soda during the Bayer’s process.
(b) Write a balanced chemical equation representing the reaction between bauxite and caustic soda during the Bayer’s process.
Anil is a laboratory assistant in a college. He prepared nitric acid but stored it in a transparent container exposed to sunlight. After a few days, brown fumes were observed in the container and the acid turned slightly yellowish in colour.
(a) What was the error made by Anil while storing the acid?
(b) Why were brown fumes observed in the container?
(c) How can the yellowish tinge in the acid be removed?
State whether the following statements are True or False.
(a) Organic compounds having different molecular formula, but same structural formula are called isomers.
(b) A salt is a compound formed by partial or complete replacement of the hydrogen ion of an acid by a metal or electropositive ion.