Chapter 19, Problem 19.117P

Interpretation Introduction

Interpretation:

Molarity of TRIS and the $\text{pH}$ of the buffer have to be determined. 

Concept Introduction:

Limiting Reagent:

The limiting reagent in a chemical reaction is the substance that is totally consumed when the chemical reaction is completed.

Calculation of Moles:

$No.ofmoles\left(n\right)=\frac{W}{M.W}$

Where,

$\begin{array}{l}W =Weightofagivencompound\\ \\ \begin{array}{l}M.W=Molecularweightofthesamecompound\hfill \\ \hfill \end{array}\end{array}$

$No.ofmoles\left(n\right)=\left(Molarity\right)\left( Volume\right)$

Molarity:

Molarity or molar concentration is the number of moles of solute dissolved per liter of solution, which can be calculated using the following equation,

$Molarity=\frac{\text{moles of solute}}{\text{volume of solution in L}}$

Henderson-Hasselbalch Equation:

The Henderson-Hasselbalch Equation can be written for any conjugate acid–base pair as given bellow,

$pH=p{K}_a+\log \left(\frac{\left[Base\right]}{\left[Acid\right]}\right)$

$p{K}_{{}_a}+p{K}_b=14$

Where,

$\begin{array}{l}\text{pH}\text{=}\text{-log}\left[{\text{H}}_{\text{3}}{\text{O}}^{\text{+}}\right]\\ \\ {\text{pK}}_{\text{a}}\text{=}{\text{-logK}}_{\text{a}}\\ \\ {\text{pK}}_{\text{b}}\text{=}{\text{-logK}}_{\text{b}}\\ \\ {\text{K}}_{\text{a}}\text{=}\text{Dissociation constant}\text{of}\text{acid}\\ \\ {\text{K}}_{\text{b}}\text{=}\text{Dissociation constant of base}\\ \\ \left[\text{Base}\right]\text{=}\text{Concentration of base}\\ \\ \left[\text{Acid}\right]\text{=}\text{Concentration of acid}\end{array}$