Acids, Bases, and Reactions: A Comprehensive Guide for GCSE Chemistry

Understanding Acids and Bases In chemistry, acids and bases play a crucial role in various chemical reactions. An acid is a substance that releases hydrogen ion...

Understanding Acids and Bases

In chemistry, acids and bases play a crucial role in various chemical reactions. An acid is a substance that releases hydrogen ions (H+) in an aqueous solution, while a base is a substance that releases hydroxide ions (OH-).

The pH Scale

The pH scale measures the acidity or basicity of a solution. It ranges from 0 to 14, with 7 being neutral. Solutions with a pH less than 7 are acidic, while those with a pH greater than 7 are basic or alkaline.

Neutralization Reactions

When an acid and a base react, they undergo a neutralization reaction. In this process, the hydrogen ions from the acid combine with the hydroxide ions from the base to form water. The products of a neutralization reaction are a salt and water.

Worked Example

Reaction: HCl (hydrochloric acid) + NaOH (sodium hydroxide) → NaCl (sodium chloride) + H2O (water)

Balanced Equation: HCl + NaOH → NaCl + H2O

Reactivity Series and Metal Extraction

The reactivity series is a list of metals arranged in order of their reactivity. Metals higher in the series are more reactive and can displace less reactive metals from their compounds in a displacement reaction.

Metal Extraction

Metals can be extracted from their ores using various methods, including oxidation/reduction reactions. The method used depends on the metal's position in the reactivity series and the economic feasibility of the process.

Electrolysis

Electrolysis is a process that separates compounds into their respective elements using an electric current. It can be performed on molten or aqueous ionic compounds and has various practical applications, such as metal extraction and purification.

Half Equations

Half equations represent the oxidation or reduction processes occurring at each electrode during electrolysis. They are useful for understanding and balancing redox reactions.

Worked Example

Electrolysis of Molten NaCl:

Anode (Oxidation): 2Cl- → Cl2 + 2e-

Cathode (Reduction): 2Na+ + 2e- → 2Na

#acids #bases #pH #reactions #neutralization
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📚 Category: GCSE Chemistry
Last updated: 2025-11-03 15:02 UTC