Problem 27 - Chemistry Class 9

Question

What is the total charge of 2 moles of electrons in faraday?

Step-by-Step Solution

Answer

Answer: The total charge of 2 moles of electrons is 192970 Coulombs.

Step 1: Find the number of moles of electrons

We're given that there are 2 moles of electrons.

Step 2: Determine Faraday's constant

Faraday's constant (F) represents the total electric charge carried by one mole of electrons. F ≈ 96485 Coulombs/mol.

Step 3: Calculate the total charge

To find the total charge of 2 moles of electrons in faradays, we will multiply the number of moles by Faraday's constant: Total Charge = Number of moles × Faraday's constant Total Charge = 2 mol × 96485 Coulombs/mol Total Charge = 192970 Coulombs So, the total charge of 2 moles of electrons is 192970 Coulombs.

Key Concepts

Mole Concept

Understanding the mole concept is crucial in chemistry as it provides a link between the microscopic world of atoms and the macroscopic world we observe. A mole can be thought of as a ‘chemical dozen’. Just as a dozen represents 12 items, a mole represents approximately 6.022 × 10^23 particles (Avogadro’s number). This concept allows chemists to count atoms, ions, and molecules in bulk quantities for practical use, such as in reactions and stoichiometry.

In our example problem, we're dealing with moles of electrons. Electrons are subatomic particles and cannot be counted directly, but by using the mole concept, we can work with a measurable quantity. When we say we have '2 moles of electrons,' we are referring to two times Avogadro's number of electrons, which is a vast number of particles—about 1.2044 × 10^24 electrons in this case.

Electric Charge

Electric charge is a fundamental property of matter that causes it to experience a force when placed in an electromagnetic field. There are two types of charge, positive and negative, and they are carried by protons and electrons, respectively. Electric charge is measured in the SI unit called the Coulomb (C).

The charge of a single electron is approximately -1.602 × 10^(-19) Coulombs. Although this charge is minuscule, when dealing with a mole of electrons, the total charge becomes significant. In the problem we discussed, Faraday's constant approximately 96485 C/mol represents the total charge of one mole of electrons. When calculating electric charge in chemistry, we typically deal with bulk quantities of charges, which are easier to measure and work with than individual charges on particles.

Chemistry Calculations

Chemistry calculations often involve using fundamental constants, such as Faraday's constant, to bridge the gap between theoretical concepts and real-world measurements. These calculations can pertain to molar masses, reaction yields, concentration, and, as shown in our problem, electric charges.

To compute the total charge of two moles of electrons, we multiplied the quantity (2 moles) by Faraday's constant. This showcases how constants serve as conversion factors in chemistry. Through such calculations, we can predict and quantify the outcomes of chemical reactions or physical processes, such as the yield of a product produced in a reaction or the electric charge transferred during an electrochemical reaction.