The molecular formula for Barium chromate is BaCrO4.
The Correct Answer and Explanation is:
Correct Answer:
The molecular formula for Barium chromate is BaCrO₄.
Explanation
Barium chromate is an inorganic compound composed of the elements barium (Ba), chromium (Cr), and oxygen (O). The molecular formula BaCrO₄ reflects its composition and reveals that it consists of one barium ion and one chromate ion.
Barium is an alkaline earth metal found in Group 2 of the periodic table. It commonly forms a +2 cation (Ba²⁺) due to the loss of its two outermost electrons. Chromium in this compound is part of the chromate ion, CrO₄²⁻, which is a polyatomic ion where chromium is in the +6 oxidation state. The chromate ion contains one chromium atom centrally bonded to four oxygen atoms in a tetrahedral arrangement.
The charges on the barium ion (+2) and the chromate ion (−2) balance each other out in a 1:1 ratio. This charge neutrality results in the empirical and molecular formula BaCrO₄. Since the compound is composed of ions, it is classified as an ionic compound.
Barium chromate appears as a yellow powder and is known for its role as a pigment, corrosion inhibitor, and oxidizing agent. It is insoluble in water, which distinguishes it from many other chromate salts. This insolubility is due to the strong ionic interactions between the barium cation and the chromate anion, which prevent the ions from dissociating easily in water.
In terms of safety and environmental impact, barium chromate is considered toxic and potentially carcinogenic due to the presence of hexavalent chromium. Proper handling procedures and protective equipment are essential when working with this compound to prevent exposure through inhalation, ingestion, or skin contact.
Understanding the molecular formula BaCrO₄ provides insight into both the chemical structure and the behavior of this compound in various chemical reactions and industrial applications.
