How many grams of NaOH must be added to 1.00 L of a buffer made from 0.150 M NH3 and 10.0 g of

step 1 Okay, so we've got a buffer. So let's start by finding out the moles of the two components of ou

How many grams of NaOH must be added to 1.00 L of a buffer...

How many grams of $\mathrm{NaOH}$ must be added to $1.00 \mathrm{~L}$ of a buffer made from $0.150 \mathrm{M} \mathrm{NH}_{3}$ and $10.0 \mathrm{~g}$ of $\mathrm{NH}_{4} \mathrm{Cl}$ so that the $\mathrm{pH}$ increases by one unit (e.g., from 5 to 6 )? $K_{\mathrm{a}}$ for $\mathrm{NH}_{4}{ }^{+}$ is $5.6 \times 10^{-10}$.

Key Concepts

Relationship between pKa and pH

The pKa value of the weak acid is a measure of its acid strength and helps determine the pH of the buffer solution via the Henderson?Hasselbalch equation. A change in the ratio of conjugate base to acid by a factor corresponding to a one-unit change in pH can be calculated using this relationship.

Acid-Base Equilibrium

Acid-base equilibrium describes the reversible reaction between a weak acid and its conjugate base. In the context of a buffer, the addition of a strong base shifts the equilibrium by converting some of the weak acid into its conjugate base, thereby altering the pH.

Reaction Stoichiometry in Buffer Systems

When a strong base is added to a buffer, it reacts with the weak acid component in a 1:1 molar ratio to produce the conjugate base and water. Accounting for this stoichiometric reaction is key to quantifying how much reagent is needed to achieve a desired pH change.

Henderson?Hasselbalch Equation

This equation relates the pH of a buffer solution to the pKa of the weak acid and the ratio of the concentrations of its conjugate base and acid. It is essential for calculating how changes in the amounts of acid or base in the buffer affect the pH.

Buffer Solutions

Buffer solutions consist of a weak acid and its conjugate base (or a weak base and its conjugate acid) that work together to resist changes in pH upon the addition of small amounts of strong acids or bases. Understanding their composition and behavior is crucial for predicting the effect of adding reagents like NaOH.

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