What will be the pH of a solution formed by mixing 40 ml of 0.10 M HCl with 10 ml of 0.45 M NaOH

We know that number of moles= molarity x volume For NaOH= 0.45x0.01=0.0045 mol For HCl= 0.1 x0.04= 0.004 mol 2 HCl NaOH NaCl H O -> For complete neutralization, excess amount of NaOH present= 0.0045-0.004mol= 0.0005 moles. Also, total volume = 0.04+0.01= 0.05L Now, concentration of hydroxyl ions = 0.0005/0.05= 0.01M pOH log pOH 2 pH pOH 14 pH 14 2 12 (0.01) pH Calculation of Weak Acids and Bases