Gayathri Mani

Strong and Weak Electrolytes Study Guide

Electrolytes are substances that become ions when they get dissolved in water.

INTRODUCTION:

Where do we use electrolytes in daily life? Take a guess. Don't we use salt in our food? That's an electrolyte. Those special sports drinks offered to athletes are also electrolytes. The detergent we use for washing our clothes is once again an electrolyte. These are a few instances wherein electrolytes play an important role in our day-to-day lives.

Electrolytes in Energy Drinks Source

BUT THE QUESTION ARISES: WHAT IS AN ELECTROLYTE?

Electrolytes are substances that become ions (an atom or molecule with a net electrical charge) when they get dissolved in water and acquire the capacity to conduct electricity. A positively charged ion is called a cation, whereas a negatively charged ion is called an anion.

Based on ionization (dissociation into constituent ions) in an aqueous solution, electrolytes are of 2 types: strong and weak.

Electrolytes Source

STRONG ELECTROLYTE:

Strong acids, bases, and salts are examples of strong electrolytes. In an aqueous solution, these compounds dissociate into ions.

EXAMPLES:

  • HCl - Hydrochloric acid
  • HBr - Hydrobromic acid
  • HI - Hydroiodic acid
  • NaOH - Sodium hydroxide
  • NaCl - Sodium chloride

WEAK ELECTROLYTE:

In water, weak electrolytes only partially disintegrate into ions. Weak acids, bases, and a range of other substances are examples of weak electrolytes. The majority of nitrogen-containing substances are weak electrolytes.

EXAMPLES:

  • HF - Hydrofluoric acid
  • CH₃CO₂H - Acetic acid
  • NH₃ - Ammonia
  • H₂O - Water

WEAK ELECTROLYTE Source

CONCLUSION:

  • An electrolyte is a substance that dissolves in water and acquires the capacity to conduct electricity.
  • There are two types of electrolytes- strong and weak electrolytes.
  • A strong electrolyte is an electrolyte that dissolves almost completely in water. An example of a strong electrolyte is Hydrogen Chloride (HCl).
  • A weak electrolyte is an electrolyte that doesn't dissolve completely in water.

FAQs:

1. Is HCl acid a strong electrolyte?

Yes, hydrogen chloride is a strong electrolyte, and it dissolves in water completely to form Hydrogen ions and chlorine ions.

2. Why is HCl an electrolyte?

HCl is an electrolyte because it completely dissolves to form hydrogen ions and chloride ions when mixed with water. These together conduct electricity. Hence, it's an electrolyte.

3. When does HCl act as a non-electrolyte?

In its pure form, HCl gas is a non-electrolyte. Electrolytes are formed once it's dissolved in water. Since hydrogen chloride gas is not dissolved in water, it's a non-electrolyte.

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SOURCES:

  1. Strong and Weak Electrolytes. https://www.ck12.org/c/chemistry/strong-and-weak-electrolytes/lesson/Strong-and-Weak-Electrolytes-CHEM/ accessed 17 Feb 2022
  2. Chemistry Examples: Strong and Weak Electrolytes. https://www.thoughtco.com/strong-and-weak-electrolytes-609437 accessed 17 Feb 2022