Which polyatomic ions are anions?
A Hypochlorite
B Acetate
C Ammonium
D Bicarbonate
E Nitrite
F Hydroxide
The correct answer and explanation is:
Correct Answers:
A. Hypochlorite
B. Acetate
D. Bicarbonate
E. Nitrite
F. Hydroxide
Explanation:
Polyatomic ions are charged groups of covalently bonded atoms that behave as a unit. These ions can either carry a positive charge (cations) or a negative charge (anions). An anion is a negatively charged ion, which means it has gained one or more electrons.
Let us examine each of the listed ions:
- Hypochlorite (ClO⁻): This ion consists of chlorine and oxygen, carrying a negative charge. It is an anion and commonly found in bleaching agents and disinfectants.
- Acetate (C₂H₃O₂⁻ or CH₃COO⁻): This negatively charged ion is derived from acetic acid. It is an anion and commonly found in vinegar and biological metabolic processes.
- Ammonium (NH₄⁺): This is a cation, not an anion. It carries a positive charge and is formed when ammonia accepts a proton. It is commonly found in fertilizers and cleaning products.
- Bicarbonate (HCO₃⁻): This is a negatively charged ion formed when carbonic acid loses one hydrogen ion. It is an important buffer in blood and other biological fluids, making it an anion.
- Nitrite (NO₂⁻): This negatively charged ion contains nitrogen and oxygen. It is an anion and often occurs in food preservatives and the nitrogen cycle.
- Hydroxide (OH⁻): This ion carries a negative charge and consists of oxygen and hydrogen. It is a strong base and is classified as an anion.
In summary, all the listed ions are anions except ammonium, which is a cation. Understanding the charge of polyatomic ions is important in predicting chemical behavior, bonding, and how compounds will form in solutions.