Chapter 3, Problem 3.CE

(a)

Interpretation Introduction

Interpretation:

The volume of $53.4(\pm 0.4)\text{ wt\%}$ $\text{NaOH}$ needed to prepare $2.000\text{ L}$ of $0.169\text{ M}$ $\text{NaOH}$ has to be calculated.

Concept Introduction:

$\begin{array}{l}\text{Density =}\frac{\text{mass}}{\text{volume}}\\ \text{Moles =}\frac{\text{mass}}{\text{molar mass}}\\ \text{Molarity =}\frac{\text{No}\text{. of moles}}{\text{litre}}\end{array}$

To Calculate: The volume of $53.4(\pm 0.4)\text{ wt\%}$ $\text{NaOH}$ needed to prepare $2.000\text{ L}$ of $0.169\text{ M}$ $\text{NaOH}$

(b)

Interpretation Introduction

Interpretation:

The absolute uncertainty in the molarity of $\text{NaOH}$ has to be calculated.

Concept Introduction:

Uncertainty:

Uncertainty means state of not certain in predicting a value.  In a measured value, the last digit will have associated uncertainty. Uncertainty has two values, absolute uncertainty and relative uncertainty.

Absolute uncertainty:

Expressed the marginal value associated with a measurement

Relative uncertainty:

Compares the size of absolute uncertainty with the size of its associated measurement

$\text{Relative uncertainty = }\frac{\text{absolute uncertainty}}{\text{magnitude of measurement}}$

To Calculate: The absolute uncertainty in the molarity of $\text{NaOH}$