A: 1M solution and 1 molal solution contain same mass of solute.
R: 1M and 1m aqueous solution are equally concentrated.

Answer

To solve the question, we need to analyze the assertion and reason provided:

**Assertion (A):** A 1M solution and a 1 molal solution contain the same mass of solute.
**Reason (R):** 1M and 1m aqueous solutions are equally concentrated.

### Step-by-Step Solution:

1. **Understanding Molarity (M):**
- Molarity (M) is defined as the number of moles of solute per liter of solution.
- A 1M solution means there is 1 mole of solute in 1 liter of solution.

2. **Understanding Molality (m):**
- Molality (m) is defined as the number of moles of solute per kilogram of solvent.
- A 1 molal solution means there is 1 mole of solute in 1 kilogram of solvent.

3. **Mass of Solute:**
- In both cases (1M and 1m), the number of moles of solute is the same (1 mole).
- Therefore, the mass of solute can be calculated using the molar mass of the solute. If the molar mass is \(M_{solute}\), then the mass of solute in both cases is:
\[ \text{Mass of solute} = 1 \text{ mole} \times M_{solute} \]
- Since both solutions contain 1 mole of solute, they contain the same mass of solute.

4. **Concentration Comparison:**
- The concentration of a solution is defined as the amount of solute per unit volume of solution.
- In a 1M solution, the total volume is 1 liter, which includes both the solute and the solvent.
- In a 1 molal solution, the solvent is 1 kg (or 1 liter, assuming the density of water is approximately 1 g/mL), but the total volume of the solution will be slightly more than 1 liter due to the addition of the solute.

5. **Conclusion on Concentration:**
- Since the volume of the 1M solution is exactly 1 liter, while the volume of the 1 molal solution is slightly more than 1 liter, the concentration of the 1M solution is greater than that of the 1 molal solution.
- Therefore, the assertion is true, but the reason is false.

### Final Answer:
- **Assertion (A) is True.**
- **Reason (R) is False.**