Chapter 8, Problem 129QRT

(a)

Interpretation Introduction

Interpretation:

Partial pressure of formaldehyde has to be determined.

Concept Introduction:

Mole fraction: Quantity which defines the number of moles of a substance in a mixture divided by the total number of moles of all substances present.

${\text{X}}_{\text{a}}\text{=}\frac{{\text{n}}_{\text{a}}}{{\text{n}}_{\text{total}}}$

Partial pressure of a gas in the mixture of gases is the product of mole fraction of the gas and the total pressure.

  ${\text{P}}_{\text{a}}\text{=}{\text{X}}_{\text{a}}\text{×}{\text{P}}_{\text{total}}$

(b)

Interpretation Introduction

Interpretation:

Number of molecules of formaldehyde in $1{\text{ cm}}^3$ of air has to be determined.

(c)

Interpretation Introduction

Interpretation:

Number of molecules of formaldehyde in the room has to be determined.