Question

A concentration of 0.1 % is equivalent to how many parts per million (ppm)?

• A. 1 ppm
• B. 10 ppm
• C. 100 ppm
• D. 1000 ppm

Hint:

To convert percentage to ppm quickly, move the decimal point four places to the right. For example, 0.1% becomes 1,000 ppm.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
In water quality management, toxicology, and aquaculture, chemical concentrations are often expressed in percentages (%) or parts per million (ppm).
Being able to convert between these units is essential for calculating chemical dosages, treatments, and pollutant levels.
Key Formula or Approach:
The conversion between percentage concentration and parts per million is based on the following relationship:
\[ 1\% = 10,000 \text{ ppm} \]
To convert any percentage to ppm, multiply the percentage value by 10,000:
\[ \text{ppm} = \text{Percentage} \times 10,000 \]

Step 2: Detailed Explanation:
Let us apply this formula to the given concentration of 0.1%:
\[ \text{ppm} = 0.1 \times 10,000 \]
\[ \text{ppm} = 1,000 \]
To understand this visually:
- 100% concentration represents 1,000,000 parts per million (the entire volume).
- 1% concentration represents 10,000 parts per million.
- 0.1% concentration represents 1,000 parts per million.
- 0.01% concentration represents 100 parts per million.
- 0.001% concentration represents 10 parts per million.
- 0.0001% concentration represents 1 part per million.
Therefore, a 0.1% concentration is equal to 1,000 ppm.

Step 3: Final Answer:
A concentration of 0.1% is equal to 1,000 ppm.
Thus, the correct choice is (D).