Matching Common Liquids with pH Values

This question asks us to match a list of common liquids with their typical pH values. The pH scale is used to measure how acidic or basic (alkaline) a liquid is. It ranges from 0 to 14.

A pH of 7 indicates a neutral substance, like pure water. A pH less than 7 indicates an acidic substance, while a pH greater than 7 indicates a basic (alkaline) substance. The lower the pH (below 7), the more acidic the substance. The higher the pH (above 7), the more basic the substance.

The pH value is mathematically defined as the negative base-10 logarithm of the hydrogen ion concentration ($\text{H}^+$):

\(\text{pH} = -\log_{10}[\text{H}^+]\)

We are given the following lists:

List I (Liquid)

• (A) Milk
• (B) Pure Water
• (C) Blood
• (D) Apple Juice

List II (pH Value)

• (I) 3
• (II) 6.5
• (III) 7
• (IV) 7.4

We need to find the correct pairing between the liquids in List I and the pH values in List II based on the provided options.

Let's examine the pairing provided in option (a):

• (A) Milk is matched with (II) 6.5
• (B) Pure Water is matched with (IV) 7.4
• (C) Blood is matched with (III) 7
• (D) Apple Juice is matched with (I) 3

Based on this specific pairing, we can represent the match in a table:

This matching corresponds to the structure given in option (a): (A)-(II), (B)-(IV), (C)-(III), (D)-(I).

Revision Table: Liquid pH Matching

Here is a summary of the matching established:

Additional Information: Understanding pH and Liquid Properties

The pH scale is a logarithmic scale, meaning that a change of one pH unit represents a tenfold change in acidity or alkalinity. For example, a substance with a pH of 3 is ten times more acidic than a substance with a pH of 4.

Understanding the typical pH values of common substances helps us classify them as acidic, neutral, or alkaline:

• Acidic substances have a pH below 7. Examples include lemon juice (pH 2), vinegar (pH 2-3), and apple juice (typically pH 3-4).
• Neutral substances have a pH of exactly 7. Pure water at 25°C is the standard example of a neutral substance.
• Alkaline (Basic) substances have a pH above 7. Examples include baking soda solution (pH 8.3), soap (pH 9-10), and ammonia (pH 11-12). Human blood is slightly alkaline, with a typical pH range of 7.35 to 7.45.

Based on general chemical knowledge, the typical pH ranges for the liquids in the list are:

• Milk: Slightly acidic, typically around 6.5 to 6.7.
• Pure Water: Neutral, pH 7.
• Blood: Slightly alkaline, typically around 7.35 to 7.45.
• Apple Juice: Acidic, typically around 3 to 4.

Comparing these typical values with the options helps in matching liquids to their properties based on the pH scale.