Which one of the following statements concerning the mole is false?

Options

A. The mole is related to Avogadro's number.
B. The mole is defined in terms of the carbon-12 isotope.
C. The mole is the SI base unit for expressing the "amount of a substance.
D. One mole of a substance has the same mass as one mole of any other substance.

Answer

To determine which statement concerning the mole is false, we need to analyze the definitions and properties associated with the mole. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Definition of a Mole
A mole is a unit in chemistry that quantifies the amount of substance. One mole contains exactly \(6.022 \times 10^{23}\) entities (atoms, molecules, ions, etc.), which is known as Avogadro's number.

**Hint:** Recall that a mole is similar to a dozen, which is a fixed quantity (12 items).

### Step 2: Analyze the Statements
We need to evaluate the statements provided regarding the mole. The statements to consider are:
1. Mole is related to Avogadro's number.
2. Mole is defined in terms of the carbon-12 isotope.
3. One mole of substance has the same mass as one mole of another substance.
4. Mole is the SI unit of expression for the amount of substance.

**Hint:** Compare each statement with the definition of a mole and known scientific principles.

### Step 3: Identify the False Statement
- **Statement 1:** True. A mole is indeed related to Avogadro's number.
- **Statement 2:** False. While the mole is often defined using carbon-12, it is not exclusively defined in terms of carbon-12 isotopes. The mole can refer to any substance.
- **Statement 3:** True. One mole of any substance has a mass equal to its molar mass in grams, but the mass will differ between different substances.
- **Statement 4:** True. The mole is the SI unit for the amount of substance.

**Hint:** Look for the statement that incorrectly describes the definition or properties of the mole.

### Step 4: Conclusion
The false statement is that the mole is defined solely in terms of the carbon-12 isotope. Therefore, the correct answer is option B.

**Final Answer:** The false statement concerning the mole is that it is defined in terms of the carbon-12 isotope.