Question

Solutions containing copper(II) ions are bright blue in color. When sodium hydroxide is added to such a solution, a solid material forms that is colored a much paler shade of blue than the original solution of copper(II) ions. The fact that a reaction takes place when sodium hydroxide is added to a solution of copper(II) ions is a ___ property.

Short answer

The fact that a reaction takes place when sodium hydroxide is added to a solution of copper(II) ions is a \textbf{chemical} property.

Step-by-step solution

Identify the reactants in the reaction

In this exercise, there are two reactants involved in the chemical reaction: a solution containing copper(II) ions and sodium hydroxide.

Understand the chemical reaction

When sodium hydroxide is added to a solution containing copper(II) ions, a solid material forms with a paler shade of blue. This indicates that a chemical reaction has taken place between the reactants, resulting in the formation of a new product.

Identify the property associated with chemical reactions

The fact that a reaction takes place when sodium hydroxide is added to a solution of copper(II) ions indicates a change in the chemical properties. Chemical properties are related to the substance's ability to undergo changes that transform it into different substances.

State the answer

The fact that a reaction takes place when sodium hydroxide is added to a solution of copper(II) ions is a \textbf{chemical} property.

Key concepts

Copper(II) Ions Reaction

The reaction involving copper(II) ions, typically present in bright blue solutions due to their unique electron configuration, showcases intriguing chemical behavior when they interact with other substances. One such interaction is with sodium hydroxide, a common lab chemical. Upon mixing, the solution's color changes as a paler blue precipitate forms, which is a clue to the complex chemical processes taking place.

Copper(II) ions, carrying a 2+ charge, have an affinity for hydroxide ions (OH-) from the sodium hydroxide. Through a process called a precipitation reaction, copper(II) hydroxide (\(\text{Cu(OH)}_2\)), an insoluble solid, is produced. This new compound accounts for the observed color change and precipitate formation. Understanding this reaction is crucial as it's a fundamental example of how transition metal ions behave in aqueous solutions with the introduction of hydroxide ions. This chemical behavior can be predictive in various industries, from mining to pharmaceuticals.

Chemical Reactions

At the heart of the described scenario lies a chemical reaction, an essential concept in chemistry that involves the conversion of reactants into products through the creation or breaking of chemical bonds. Chemical reactions can be signified by changes in color, the formation of a precipitate, evolution of gas, or temperature changes. In our copper(II) ion example, the paler blue precipitate is a hallmark of a chemical reaction taking place, demonstrating the transformation of reactants into a new substance.

Chemical reactions are classified into types such as synthesis, decomposition, single replacement, double replacement, and combustion. The copper(II) ions reacting with sodium hydroxide illustrate a double replacement reaction, where components of the reactants exchange partners to form new compounds. Knowledge of these reactions is crucial as it allows one to predict the outcomes of mixing different chemicals, which is beneficial for tasks ranging from developing new materials to environmental remediation.

Sodium Hydroxide Chemistry

Sodium hydroxide, also known as lye or caustic soda, plays a significant role in chemical laboratories and industrial processes. It is a strong alkali, meaning it has a high pH and can neutralize acids, making it invaluable in titrations to determine acid concentration. Its reactivity with metal ions, as seen in the reaction with copper(II) ions, is just one demonstration of its chemical versatility.

In addition to forming precipitates with certain metal ions, sodium hydroxide is also used in the manufacture of soap through a process called saponification and in the paper industry for breaking down wood into pulp. When dealing with sodium hydroxide, safety is paramount due to its corrosivity, emphasizing the need to understand chemical properties to handle substances responsibly and effectively in chemical practices.