National Council Of Examiners For Engineering And Surveying (NCEES) Fundamentals Of Engineering (FE) Chemical Practice Exam

The phosphate ion is correctly represented by the formula PO4 -3. This indicates that the phosphate ion consists of one phosphorus atom (P) and four oxygen atoms (O), carrying a total negative charge of three. In this formulation, phosphorus is in the center, covalently bonded to four oxygen atoms. The -3 charge signifies that the ion has three more electrons than protons, resulting in its anionic nature. This charge distribution affects the ion's reactivity and interactions with other ions and compounds, which is an important aspect to understand in chemical reactions, especially in biological and environmental contexts. Recognizing the correct charge of the phosphate ion is crucial for understanding how it participates in various compounds, such as in biology where it plays a key role in energy transfer as part of ATP, and in environmental chemistry where it is a significant nutrient contributing to the growth of aquatic plants. The other options present different arrangements or charges that do not accurately represent the phosphate ion. For instance, PO4 +3 suggests a positively charged species, which is not typical for phosphate, while PO3 -3 indicates a different ion known as phosphite, not phosphate. The formula PO4 0 implies a neutral charge, which does not correspond to the established identity of