Question

What is the formula for the perchlorate ion? What is the origin of perchlorate ion in U.S. drinking water?

Short answer

The formula is \( ext{ClO}_4^- \). Perchlorate in water comes from industrial products like rocket fuel and explosives.

Step-by-step solution

Understanding the Perchlorate Ion

The perchlorate ion is an oxyanion of chlorine. It is present in chemical compounds where chlorine is bonded to oxygen atoms. The molecular formula for the perchlorate ion is usually written as \( ext{ClO}_4^- \), where the chlorine atom is central, bonded to four oxygen atoms, and the ion carries an overall negative charge.

Origin of Perchlorate Ion in Water

Perchlorate ions can enter the drinking water supply through various means. They are primarily introduced through the manufacturing and usage of industrial products such as rocket fuel, fireworks, and explosives. Perchlorates are highly soluble in water and do not easily degrade, leading to their presence in groundwater and surface water sources.

Impact on Drinking Water

Due to its industrial origins and stability in water, perchlorate contamination has been detected in several regions across the U.S. This contaminant can persist over time, complicating efforts to manage and remove it from drinking water supplies.

Key concepts

Oxyanion

An oxyanion is a type of polyatomic ion that contains one or more oxygen atoms combined with another element. In the case of the perchlorate ion, this is a chlorine atom. Oxyanions typically carry a charge due to the presence of extra electrons. These ions are named based on the central atom and the number of oxygen atoms attached. For perchlorate, the chemical formula is \( \text{ClO}_4^- \), where chlorine is surrounded by four oxygen atoms, and the overall negative charge is due to the extra electron. Oxyanions are fundamental in chemistry due to their role in a wide variety of chemical reactions.

Chemical Bonding

Chemical bonding refers to the process where atoms connect to form molecules and compounds. In the perchlorate ion, bonding involves the central chlorine atom forming a structure with four oxygen atoms. These bonds are covalent, meaning they involve the sharing of electrons between chlorine and oxygen. In covalent bonds, atoms achieve stability by sharing electrons rather than transferring them as in ionic bonds. The shared electrons in perchlorate allow it to maintain a stable ion structure with appropriate charge distribution. This bonding greatly influences the ion's reactivity and interactions with other chemical species in different environments.

Water Contamination

Water contamination occurs when harmful substances enter water sources, making them unsafe or unsuitable for human use and environmental health. Perchlorate, being used in industrial products like rocket fuel and fireworks, finds its way into water bodies quite easily. Its high solubility in water means it can travel through and persist in groundwater systems. Sources of contamination include industrial runoff, improper disposal, and agricultural practices. Once present in water, perchlorates pose a challenge due to their resistance to natural degradation, making them difficult to remove and a persistent problem for public health officials.

Drinking Water Safety

Ensuring drinking water safety is vital for public health. Contaminants like perchlorate in drinking water have raised concerns due to their potential health effects. Regulatory bodies set limits for safe levels of various contaminants to protect consumers. Techniques to manage perchlorate contamination include advanced filtration, biological treatments, and careful monitoring of water sources. Awareness and regulation are key in safeguarding drinking water supplies against contamination. By understanding sources of contamination and effective management strategies, we can ensure the safety of drinking water and protect public health.