Question

Is "pure" water considered to be acidic, basic, or neutral? Explain your reasoning.

Short answer

Pure water is considered neutral because its pH is 7 at room temperature.

Step-by-step solution

Understand the pH scale

The pH scale ranges from 0 to 14. It is used to specify the acidity or basicity (alkalinity) of an aqueous solution. Acidic solutions have a pH less than 7, basic (or alkaline) solutions have a pH greater than 7, and neutral solutions have a pH of 7.

Determine the pH of pure water

'Pure' water, also known as distilled water, is water that has had many of its impurities removed through distillation. The removal of impurities does not change the pH of water. Pure water at room temperature has a pH of 7.

If the pH value of pure water

Because the pH of pure water at room temperature is 7, it is considered neutral. It is neither acidic nor basic.

Key concepts

The pH Scale

The pH scale is an important concept in chemistry. It helps us understand how acidic or basic a liquid is.
The scale ranges from 0 to 14, with 7 being the middle point, indicating neutrality.
It's a logarithmic scale, which means each whole number change represents a tenfold change in acidity or basicity. For instance:

• A liquid with a pH of 6 is ten times more acidic than a liquid with a pH of 7.
• Conversely, a liquid with a pH of 8 is ten times more basic than a liquid with a pH of 7.

The pH scale is widely used to describe the nature and behavior of solutions, guiding chemists and everyday users in various applications, from agriculture to medicine.

Neutral Solutions

Neutral solutions have a specific place on the pH scale.
They have a pH of exactly 7.
The most common neutral solution you might encounter is pure water. In these solutions, the concentration of hydrogen ions (H extsuperscript{+}) is equal to the concentration of hydroxide ions (OH extsuperscript{−}).

• This balance makes them neither acidic nor basic.
• They are neither harmful in their pH value and don't burn or cause reactions like acids and bases might.

Understanding neutral solutions is important in fields like biology and chemistry, helping to maintain balance in chemical reactions and living organisms.

Acidic Solutions

Acidic solutions are rich in hydrogen ions (H extsuperscript{+}).
Their pH values are less than 7, moving towards the lower end of the pH scale.
The more hydrogen ions present, the more acidic the solution, and thus the lower its pH. Here are some key traits:

• Common examples include lemon juice and vinegar.
• They have a sour taste and are known for their ability to corrode metals.
• In reactions, acids tend to donate hydrogen ions.

Learning about acidic solutions can help us in everyday life, such as understanding how certain foods affect our health.

Basic Solutions

Basic solutions, also known as alkaline solutions, have a different characteristic setup.
They have a pH greater than 7, extending toward the upper end of the pH scale.
Basic solutions have fewer hydrogen ions and more hydroxide ions (OH extsuperscript{−}). Let's look at what this entails:

• Examples include baking soda and soap.
• These solutions often feel slippery to the touch and have a bitter taste.
• In chemical reactions, bases tend to accept hydrogen ions.

Understanding basic solutions can aid us in various applications, from cleaning to industrial processes.