Question

Give two general properties of an acid. Give two general properties of a base.

Short answer

Acids taste sour and turn blue litmus paper red, while bases taste bitter, feel slippery, and turn red litmus paper blue.

Step-by-step solution

Identifying Properties of Acids

General properties of acids include: (1) They have a sour taste. This is a characteristic property of acids that can be observed in everyday life, such as the taste of citrus fruits like lemons, which contain citric acid. (2) They turn blue litmus paper red. Acids are known to change the color of blue litmus paper to red, which is a common experiment used to identify acidic substances.

Identifying Properties of Bases

General properties of bases include: (1) They have a bitter taste and a slippery feel. For instance, soap, which often contains bases, is slippery to the touch. (2) They turn red litmus paper blue. Bases react with red litmus paper and cause it to turn blue, which is another standard test to indicate basicity.

Key concepts

Acidic Substances

Acids are substances that exhibit certain characteristic properties which differentiate them from bases.

One trademark of an acid is its sour taste. The sourness of lemons and vinegar are classic examples of this particular trait, both due to the presence of citric acid and acetic acid, respectively. Acids also react with certain metals, releasing hydrogen gas, and they have a pH value of less than 7. Furthermore, these substances are known to conduct electricity when dissolved in water due to the ions they release. From the laboratory to the kitchen, the properties of acids have significant implications on both chemical processes and our daily lives.

Base Characteristics

Bases stand on the opposite side of the pH scale to acids and possess a unique set of characteristics.

Texture and Taste

• A slippery feel is a popularly noted feature of bases, which is why substances like soaps and detergents, which often contain bases such as sodium hydroxide, create a sleek sensation when handled.


• The taste of bases is described as bitter, although tasting chemical substances is not a safe practice.

Other characteristics include their ability to dissolve oils and fats, making them effective in cleaning products. Bases also have a pH value higher than 7 and, like acids, can conduct electricity when dissolved in water because they form ions.

Litmus Paper Test

The litmus paper test is an elementary and widely utilized method to determine the acidic or basic nature of a substance.

Acids and bases exhibit their characteristic behavior by changing the color of litmus paper: an acid turns blue litmus paper red, while a base turns red litmus paper blue. This property provides a clear and immediate visual cue regarding the pH nature of the substance in question. The litmus test, while simple, is an invaluable tool in both educational settings and professional laboratories for quick assessments of chemical acidity or basicity.

Sour Taste of Acids

The sour taste is an easily recognizable property of acids and is one of their most distinctive sensory attributes. This taste is experienced commonly through various foods and beverages that contain acids like citric acid in citrus fruits and tartaric acid in grapes.

It's this sour profile that not only distinguishes acids in taste tests, but also plays a crucial role in the culinary world, enhancing flavors and preserving food. Despite its ubiquity and usefulness, one should exercise caution when dealing with stronger acids, as their corrosive nature can be harmful.

Slippery Feel of Bases

When you think of bases, perhaps the most tactile property you could refer to is their slippery feel. This distinct sensation arises because bases are adept at breaking down oils and proteins, which can give the feeling of slipperiness when touched.

This is particularly notable with household items like soap and oven cleaner, both of which typically contain alkaline substances that facilitate cleaning through the emulsification of grease. It's wise to remember that while bases are useful in everyday life, stronger bases can be caustic and should be handled with appropriate safety precautions.