Problem 34 - Chemistry in 30 days

Question

Conductivity water is used in conductance experiments (a) It has very low conductance (b) It has high conductance (c) It has medium conductance (d) It has zero conductance

Step-by-Step Solution

Answer

(a) It has very low conductance.

Step 1: Understanding Conductivity Water

Conductivity water, often referred to as deionized water or distilled water, is water that has had most of its mineral ions removed, such as cations from sodium, calcium, iron, and copper, and anions such as chloride and sulfate.

Step 2: Analyzing Conductance in Water

Conductance in water is primarily due to the presence of ions. More ions result in higher conductance, while fewer ions result in lower conductance.

Step 3: Determining Conductance Level of Conductivity Water

Since conductivity water has had its ions removed, it has very few ions available to conduct electricity. This results in its conductance being very low.

Key Concepts

Deionized Water

Deionized water is a type of purified water where mineral ions, such as sodium, calcium, iron, and copper, have been removed. This is done using ion-exchange processes that effectively strip out these charged particles, leaving almost pure H₂O. Unlike regular tap water, deionized water lacks the conductive ions that are usually present.
This purity level makes deionized water particularly useful in laboratory settings and various applications where even tiny amounts of impurities could interfere with processes or results.
Because it is free from impurities, deionized water is often used in laboratories and industries to prevent unwanted chemical reactions.

Ions and Conductivity

The conductivity of a substance relates directly to its ability to conduct electrical current, and this is heavily dependent on the presence of ions. Ions are charged particles - either positive (cations) or negative (anions) - which can carry electrical current when dissolved in water.
In tap water or seawater, which contain a multitude of ions, conductivity is typically high. This is because ions facilitate the flow of electrical current through a solution.

• Ions present in water are responsible for conducting current.
• The higher the ion concentration, the higher the conductivity of the solution.

When regions free of ions, like deionized or distilled water, are involved, considerably lower electrical conductance is observed.

Electrical Conductance

Electrical conductance refers to a material's ability to conduct an electric current. In the context of solutions, conductance is measured in Siemens (S) and is highly dependent on the concentration and mobility of ions in a solution.
Conductance is inversely related to resistance, implying that as the conductance increases, the electrical resistance decreases, facilitating a smoother electric flow.
However, in the case of deionized water, with very few ions available, the conductance is notably low. As a result, such water acts almost as an insulator, proving ineffective for electricity conduction in the absence of additional ions.

Conductance Experiments

Conductance experiments are practical assessments done in laboratories to measure the capacity of a solution to conduct electricity. These experiments typically involve passing an electrical current through a water sample and measuring its conductance using a conductance meter.
In educational settings or research laboratories, deionized water serves as an ideal baseline due to its low inherent conductivity. It provides a controlled environment to observe how introducing ions or other variables affects conductance.

• Deionized water has minimal conductance and is used as a control or starting point.
• By adding specific salts or acids, the change in conductance can be precisely measured and analyzed.

This process teaches us the fundamental principles of electrical compatibility and the importance of ions in electrical conduction.