Question

Fill in the blanks with the correct word or words. Substance with a pH higher than 7 is called \(a(n)\) __________.

Short answer

Base

Step-by-step solution

Understanding pH Scale

The pH scale is a measure of how acidic or basic a substance is. It ranges from 0 to 14.

Acids Versus Bases

Substances with a pH less than 7 are considered acids, whereas substances with a pH greater than 7 are considered bases.

Identify the Term

According to the definition, a substance with a pH higher than 7 is referred to as a base or an alkaline substance.

Key concepts

Acids

Acids are substances with a pH less than 7. The pH scale runs from 0 to 14, and acids occupy the lower end of this scale. This scale helps us measure how acidic a substance is.
Acids are important in many natural and industrial processes.

• Common examples of acids include vinegar, which contains acetic acid, and lemon juice, which contains citric acid.
• In our bodies, stomach acid, primarily composed of hydrochloric acid, aids in digestion.

Acids can taste sour, which is a characteristic feature of most acids. They can also be corrosive, meaning they can cause damage to some materials.
It's important to handle acids carefully, as they can be strong or weak. Strong acids, like sulfuric acid, can be very harmful to skin and materials, whereas weak acids, like carbonic acid, are much milder.

Bases

Bases are substances that have a pH greater than 7. Unlike acids, bases fall on the upper half of the pH scale, ranging from just above 7 to as high as 14.
Bases are usually characterized by their bitter taste and slippery feel. They are a key component in many cleaning substances and soaps.

• An everyday example of a base is baking soda, which is used in baking and cleaning.
• Antacids, often used to neutralize stomach acid, are also types of bases.

Bases can react with acids in a neutralization reaction to form water and a salt, balancing the pH closer to neutral, which is 7. This is why bases are often used to counteract acids.
Just like acids, bases can be strong or weak. Strong bases can cause chemical burns, so it's important to handle them with care.

Alkaline Substance

The term "alkaline" is often used interchangeably with "base." Alkaline substances are those that have a pH greater than 7.
Alkalinity refers to the strength of a base.

• When you hear about alkaline water, it means the water has a pH higher than 7.
• Alkaline batteries, as the name suggests, contain an alkaline substance that makes them long-lasting compared to regular batteries.

Many plant-based foods are alkaline in nature and are recommended for their health benefits.
Understanding alkalinity can be beneficial in various fields, from cooking to environmental science, as it helps in balancing and managing pH levels in different contexts.