Chapter 4, Problem 4.25QP

Interpretation Introduction

Interpretation: The increase in the concentration of ${\text{NF}}_{\text{3}}$ over the given years is given in parts per trillion. The concentration of ${\text{NF}}_{\text{3}}$ in milligram per $\text{kg}$ of air is to be calculated.

Concept introduction: One part per trillion is equal to nanograms of the solute present in one $\text{kg}$ of the solution.

One nanograms is ${10}^{-6}$ milligrams.

Therefore, the concentration in milligrams per $\text{kg}$ is calculated by the formula,

$\text{Concentration}=\text{parts}\text{per}\text{trillion}\times {10}^{-6}$

To determine: The concentration of ${\text{NF}}_{\text{3}}$ in milligram per $\text{kg}$ of air.