Question

Determine the amounts (in mol) of benzylammonium chloride (pKa = 9.3, MW = 143.61 g/mol) and its conjugate base, benzylamine (MW = 107.156 g/mol, density = 0.981 g/mL) needed to prepare 1.44 L of 364 mM benzylamine buffer at pH 8.5. Use scientific notation to express your answer to two decimal places.

Answer 1

To determine the amounts of benzylammonium chloride and benzylamine needed to prepare the buffer, we can use the Henderson-Hasselbalch equation and the equation for buffer concentration. By substituting the given pH and pKa values into the Henderson-Hasselbalch equation, we can calculate the ratio of [A-] to [HA].

Step-by-step explanation:

To calculate the amounts of benzylammonium chloride and benzylamine needed to prepare the buffer, we need to consider the Henderson-Hasselbalch equation and the equation for buffer concentration. The Henderson-Hasselbalch equation is pH = pKa + log([A-]/[HA]), where [A-] is we can calculate the ratio of [A-] to [HA]. The equation for buffer concentration is C = n/V, where C is the concentration, n is the amount in moles, and V is the volume in liters. By substituting the equation for the ratio of [A-] to [HA] into the equation for buffer concentration, we can calculate the amounts of benzylammonium chloride and benzylamine needed in moles. Finally, we can convert moles to grams using the molecular weights of benzylammonium chloride and benzylamine.

the amounts of benzylammonium chloride and benzylamine needed to prepare the buffer, we can use the Henderson-Hasselbalch equation and the equation for buffer concentration. By substituting the given pH and pKa values into the Henderson-Hasselbalch equation, we can calculate the ratio of [A-] to [HA]. Then, by using the equation for buffer concentration and the volume of the buffer, we can calculate the amounts of benzylammonium chloride and benzylamine needed in moles. Finally, we can convert the moles to grams using the molecular weights of benzylammonium chloride and benzylamine.