chemical formula for copper i hydroxide

2 min read 23-02-2025

Copper(I) hydroxide, also known as cuprous hydroxide, is an inorganic compound with a fascinating chemistry. Understanding its chemical formula is key to understanding its properties and reactions. This article will delve into the formula, its structure, and some of its key characteristics.

Understanding the Formula: CuOH

The chemical formula for copper(I) hydroxide is simply CuOH. This tells us that each molecule of this compound contains one copper(I) ion (Cu⁺) and one hydroxide ion (OH⁻). The copper ion has a +1 charge, while the hydroxide ion has a -1 charge, resulting in a neutral molecule.

Why not Cu(OH)₂?

It's important to distinguish copper(I) hydroxide (CuOH) from copper(II) hydroxide (Cu(OH)₂). The Roman numeral I in "Copper(I)" indicates that copper is in its +1 oxidation state. In copper(II) hydroxide, copper exists in its +2 oxidation state, requiring two hydroxide ions to balance the charge. Confusing these two compounds can lead to inaccurate predictions of chemical behavior.

The Structure and Properties of CuOH

Copper(I) hydroxide is a yellowish-brown solid. However, it's notoriously unstable and readily disproportionates, meaning it spontaneously transforms into other copper compounds. This disproportionation reaction typically involves the formation of copper(II) hydroxide and elemental copper.

This instability makes studying its pure form challenging. Much of what we know about its properties comes from indirect observations and theoretical calculations. It's believed to have a polymeric structure involving bridging hydroxide ions. This means the OH groups aren't just directly bound to the copper, but also connecting different copper atoms in a chain-like formation.

Preparation and Applications of CuOH

Due to its instability, preparing pure CuOH is difficult. It’s often formed as an intermediate in reactions and quickly converts to other copper compounds. One common method involves reducing a copper(II) salt in alkaline solution. However, isolating the CuOH is difficult before it disproportionates. Consequently, practical applications of pure CuOH are limited.

Frequently Asked Questions (FAQs)

What is the molar mass of CuOH?

The molar mass of CuOH is approximately 80.55 g/mol (calculated using the atomic masses of copper, oxygen, and hydrogen).

Is CuOH soluble in water?

While its solubility is not well-defined due to its instability, it's generally considered to be sparingly soluble in water, quickly undergoing reactions instead of simply dissolving.

How is Copper(I) Hydroxide different from Copper(II) Hydroxide?

The key difference lies in the oxidation state of copper. Copper(I) hydroxide (CuOH) features copper in the +1 oxidation state, while copper(II) hydroxide (Cu(OH)₂) has copper in the +2 oxidation state. This difference significantly impacts their properties and stability. Copper(II) hydroxide is considerably more stable than copper(I) hydroxide.

Conclusion: A Unique and Unstable Compound

Copper(I) hydroxide, with its simple chemical formula CuOH, is a fascinating yet challenging compound to study due to its instability. Its unique properties and propensity to disproportionate make it a noteworthy example of the complexities in inorganic chemistry. Further research is still needed to fully understand its behavior and potential (though limited) applications.