The solution was created by dissolving .34 mol Na(OH) and 0.15 miles Ca(OH)2 in water. The final volume of the solution was 2.5 L. calculate the POH of the solution.

1 answer

To find the pOH of the solution, we first need to calculate the concentration of hydroxide ions (OH-) in the solution.

For Na(OH):
Molar mass of NaOH = 23 + 16 + 1 = 40 g/mol

0.34 mol NaOH x 40 g/mol = 13.6 g NaOH
1 L of solution with 13.6 g NaOH will have a concentration of 13.6 g/L = 0.136 g/L

For Ca(OH)2:
Molar mass of Ca(OH)2 = 40 + 2(16) + 2(1) = 74 g/mol

0.15 mol Ca(OH)2 x 74 g/mol = 11.1 g Ca(OH)2
1 L of solution with 11.1 g Ca(OH)2 will have a concentration of 11.1 g/L = 0.111 g/L

Total concentration of OH-:
0.136 g/L (from NaOH) + 0.111 g/L (from Ca(OH)2) = 0.247 g/L

Convert the concentration to mol/L:
0.247 g/L / 17 g/mol = 0.0145 mol/L

Calculate pOH:
pOH = -log[OH-] = -log(0.0145) = 1.84

Therefore, the pOH of the solution is 1.84.