Final answer:
To find the pOH of the solution, we need to first calculate the concentration of the sodium hydroxide (NaOH) solution. Given that 0.30 g of NaOH is dissolved in 3.5 L of solution, we can convert the mass to moles and calculate the concentration. Then, using the relationship pOH = -log[OH-], we can find the pOH value.
Step-by-step explanation:
To find the pOH of the solution, we need to first calculate the concentration of the sodium hydroxide (NaOH) solution. Given that 0.30 g of NaOH is dissolved in 3.5 L of solution, we can convert the mass to moles by dividing by the molar mass of NaOH. The molar mass of NaOH is 22.99 g/mol for sodium (Na), 16.00 g/mol for oxygen (O), and 1.01 g/mol for hydrogen (H). Thus, the molar mass of NaOH is 22.99 + 16.00 + 1.01 = 40.00 g/mol.
Converting 0.30 g of NaOH to moles: 0.30 g ÷ 40.00 g/mol = 0.0075 mol NaOH.
Next, we can calculate the concentration (in mol/dm³) by dividing the number of moles (0.0075 mol) by the volume of the solution in dm³ (3.5 L = 3.5 dm³).
Concentration of NaOH solution = 0.0075 mol ÷ 3.5 dm³ = 0.00214 mol/dm³.
Now, to find the pOH, we can use the relationship:
pOH = -log[OH-].
Since NaOH is a strong base and fully dissociates in water, the concentration of [OH-] is equal to the concentration of NaOH, which is 0.00214 mol/dm³.
Therefore, pOH = -log(0.00214) = 2.67.