25 mL of NaOH 0.16 M is added to 50 mL of 0.1 M HCl.
What is the concentration of hydroxide ions in the solution?
mols HCl = M x L = ?
mols NaOH = M x L = ?
Subtract. Excess mols = either mols HCl or NaOH, then determine OH or H^+ from that.
To find the concentration of hydroxide ions in the solution, we need to calculate the amount of hydroxide ions produced from the reaction between NaOH and HCl. The balanced chemical equation for this reaction is:
NaOH + HCl -> NaCl + H2O
From the equation, we can see that 1 mole of NaOH reacts with 1 mole of HCl to produce 1 mole of water. Therefore, the number of moles of NaOH is equal to the number of moles of hydroxide ions (OH-) produced.
First, let's calculate the number of moles of NaOH:
Moles of NaOH = volume (in liters) × concentration (in moles per liter)
= 25 mL × (1 L / 1000 mL) × 0.16 mol/L
= 0.004 mol
Since we have established that the number of moles of NaOH is equal to the number of moles of hydroxide ions, the concentration of hydroxide ions is the same.
Concentration of hydroxide ions = 0.004 mol / (25 mL + 50 mL)
= 0.004 mol / 0.075 L
= 0.053 M
Therefore, the concentration of hydroxide ions in the solution is 0.053 M.