If we consider that `1/6`, in place of `1/12` mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of a substance will:
a.be a function of the molecular mass of the substance
b.remain unchanged
c.increase two fold
d.decrease twice.

Options

A. be a function of the molecular mass of the substance
B. remain unchanged
C. increase two fold
D. decrease twice.

Explanation

To solve the question, we need to analyze how changing the atomic mass unit affects the mass of one mole of a substance.

### Step-by-Step Solution:

1. **Understanding the Concept of Molar Mass**:
- The molar mass of a substance is defined as the mass of one mole of that substance. It is calculated based on the mass of individual atoms or molecules and Avogadro's number (approximately \(6.022 \times 10^{23}\)).

2. **Current Definition of Atomic Mass Unit**:
- The current atomic mass unit (amu) is defined based on the mass of carbon-12, where 1 amu is defined as \(1/12\) of the mass of a carbon-12 atom.

3. **Changing the Atomic Mass Unit**:
- The question proposes changing the atomic mass unit to \(1/6\) of the mass of a carbon atom instead of \(1/12\). This means we are redefining the scale of measurement for atomic masses.

4. **Impact on Molar Mass Calculation**:
- The molar mass of a substance is calculated by multiplying the atomic or molecular mass (in amu) by Avogadro's number. Since the relationship between the atomic mass unit and the actual mass of the atoms/molecules remains proportional, the numerical value of the molar mass will change if we change the atomic mass unit.

5. **Comparative Analysis**:
- If we switch from \(1/12\) to \(1/6\), the numerical values of atomic masses will effectively double (since \(1/6\) is twice \(1/12\)). However, since the molar mass is calculated based on the atomic mass multiplied by Avogadro's number, the actual mass of one mole of the substance will remain unchanged because the proportionality is maintained.

6. **Conclusion**:
- Therefore, even though the atomic mass unit changes, the mass of one mole of a substance does not change. It remains a function of the molecular mass, which is still calculated in the same way.

### Final Answer:
- The mass of one mole of a substance will **remain unchanged**.