184_notes:examples:week2_moleoelectrons

This is an old revision of the document!


How much total charge (in coulombs) is in one mole of electrons?

Facts

  • The Avogadro constant is $6.022 \cdot 10^{23} \text{ mol}^{-1}$
    • Note: When we write the unit as $\text{ mol}^{-1}$, we mean particles per mole.
  • All electrons have the same charge, which is $e$ = $-1.602\cdot10^{-19} \text{ C}$.

Lacking

  • Total Charge

Approximations & Assumptions

  • None here, we have all the information we need.

Representations

  • The total charge $Q$ can be written as the number of particles $N$ times the charge of each particle ($e$, for electrons): $Q=N\cdot e$.

The total number of electrons $N$ is given by \begin{align*} N &= 1 \text{ mol} \cdot 6.022 \cdot 10^{23} \text{ mol}^{-1} \\ &= 6.022 \cdot 10^{23} \end{align*} We now have $N$ and $e$. The total charge $Q$ is then given by \begin{align*} Q &= N \cdot e \\ &= 6.022 \cdot 10^{23} \cdot -1.602 \cdot 10^{-19} \text{ C} \\ &= 9.647 \cdot 10^4 \text{ C} \end{align*}

  • 184_notes/examples/week2_moleoelectrons.1503595277.txt.gz
  • Last modified: 2017/08/24 17:21
  • by tallpaul