Acids and Alkalis in Household Cleaners

Study Notes

Here are the study notes:

Acids and Alkalis

Some foods, drinks, and seasonings contain acids, such as soft drinks, vinegar, tea, yoghurt, grapes, citrus fruits, and spinach.
Personal care products, household cleaners, and drugs can also contain acids, such as body lotion, hair conditioner, toilet cleaner, and aspirin.
In school laboratories, hydrochloric acid, sulphuric acid, and nitric acid are commonly used.

Safety Precautions

When handling acids and alkalis, wear safety goggles and gloves to protect eyes and skin.
Pour acidic or alkaline wastes into appropriate waste bottles.
Wash hands thoroughly after experiments.
Never taste acids or alkalis used in the laboratory.
Do not mix acids or alkalis with other chemicals without permission.

Acid-Alkali Indicators and pH Scale

Plant extracts can be used as natural indicators to distinguish between acids and alkalis.
Litmus solution or pH paper can be used to find the pH value of a substance.
The pH scale measures the acidity or alkalinity of a substance, ranging from 0 to 14.
A lower pH value indicates a more acidic substance, while a higher pH value indicates a more alkaline substance.

Neutralization

When an acid and an alkali react, a salt and water are produced, and heat is released.
The pH value of the solution changes during neutralization.
The graph shows the change of pH value when dilute sodium hydroxide solution is added to dilute hydrochloric acid.

Applications of Neutralization

Neutralization has many useful applications in daily life, such as preventing tooth decay, relieving stomach upset, treating insect stings and bites, treating industrial waste containing acids or alkalis, and regulating the pH value of soil.

Corrosive Nature of Acids

Acids react with some metals to produce a salt and hydrogen.
The reaction between an acid and a metal can be represented by a word equation: acid + metal → salt + hydrogen.
Building materials such as marble and limestone react with acids, producing a salt, carbon dioxide, and water.### Chemical Reactions
Chalk (a form of limestone) reacts with dilute hydrochloric acid to produce calcium chloride, carbon dioxide, and water.
The reaction between an acid and a carbonate can be represented by the equation: acid + carbonate → salt + carbon dioxide + water.

Acid Rain

Burning fossil fuels in power stations, factories, and vehicles produces sulphur dioxide and nitrogen oxides, which make rainwater more acidic and form acid rain.
Acid rain corrodes metal objects and building materials, damages plants, and causes harm to aquatic life.

Acids and Alkalis

Acids and alkalis can be classified into strong acids, weak acids, strong alkalis, and weak alkalis.
Examples of strong acids include hydrochloric acid, sulphuric acid, and nitric acid, while weak acids include citric acid, ethanoic acid, and carbonic acid.
Examples of strong alkalis include sodium hydroxide and potassium hydroxide, while weak alkalis include ammonia solution.

Hazards of Acids and Alkalis

Strong acids and alkalis are more corrosive than weak acids and alkalis.
Concentrated acids and alkalis are more corrosive than dilute ones.
When using household cleaners containing acids and alkalis, it is important to read safety instructions, use them in well-ventilated areas, and avoid mixing different cleaners to prevent toxic vapours.

Description

This quiz covers the properties of acids and alkalis in concentrated form, specifically in the context of household cleaners. Learn about the corrosive nature of these substances and how to handle them safely.