A concentration of 1 ppm means that

Options

A. 1 kg of solution contains 1 mg of solute
B. 1 kg of solution contains 1 g of solute
C. 1 kg of solution contains 1 mL of solute
D. 1 g of solution contains 1 g of solute

Answer

To solve the question regarding what a concentration of 1 ppm means, we can break it down step by step.

### Step-by-Step Solution:

1. **Understanding PPM**:
- PPM stands for "parts per million." It is a way to express very dilute concentrations of substances.
- It indicates how many parts of a substance (solute) are present in a million parts of the solution.

2. **Conversion to Mass**:
- To express 1 ppm in terms of mass, we can use the definition: 1 ppm is equivalent to 1 milligram of solute per liter of solution.
- This means that if you have 1 liter of solution, it contains 1 mg of solute.

3. **Relating Volume to Mass**:
- Since the density of water is approximately 1 kg/L, we can say that 1 liter of water weighs about 1 kg.
- Therefore, 1 liter of solution can also be considered as 1 kg of solution.

4. **Final Interpretation**:
- Thus, if 1 liter (or 1 kg) of solution contains 1 mg of solute, we can conclude that:
- A concentration of 1 ppm means that 1 kg of solution contains 1 mg of solute.

5. **Choosing the Correct Option**:
- Among the options provided in the question, the correct interpretation of 1 ppm is:
- **1 kg of solution contains 1 mg of solute**.

### Conclusion:
The concentration of 1 ppm means that 1 kg of solution contains 1 mg of solute.