Calculate the concentration of a sodium oxalate solution in mol dm⁻³ given its chemical formula and atomic masses, but without the mass of solute or volume of solution.

The relative atomic masses are given as $\text{Na} = 23$, $\text{C} = 12.0$, and $\text{O} = 16.0$.

$$\text{Molar mass of } \text{Na}_2\text{C}_2\text{O}_4 = (2 \times \text{Na}) + (2 \times \text{C}) + (4 \times \text{O})$$ $$\text{Molar mass} = (2 \times 23) + (2 \times 12.0) + (4 \times 16.0)$$ $$\text{Molar mass} = 46 + 24.0 + 64.0$$ $$\text{Molar mass} = 134.0 \text{ g/mol}$$

The concentration in $\text{mol dm}^{-3}$ (molarity) is calculated using the formula:

$$\text{Concentration} = \frac{\text{Number of moles of solute}}{\text{Volume of solution in dm}^3}$$

The number of moles can be found using:

$$\text{Number of moles} = \frac{\text{Mass of solute}}{\text{Molar mass of solute}}$$

The question provides the chemical formula and atomic masses, allowing us to calculate the molar mass. However, it does not provide the mass of sodium oxalate used or the volume of the solution. Without these values, the numerical concentration cannot be determined.

Therefore, the concentration of the sodium oxalate solution cannot be calculated with the information provided. You would need either the mass of $\text{Na}_2\text{C}_2\text{O}_4$ dissolved and the volume of the solution, or the number of moles of $\text{Na}_2\text{C}_2\text{O}_4$ and the volume of the solution.

The molar mass of sodium oxalate is $\text{134.0 g/mol}$.