This question shows you how to find the free electron number density for copper

CHEMISTRY · Multi-part · ISC · Chemistry · Some Basic Concepts of Chemistry · Mole concept

Problem

This question shows you how to find the free electron number density for copper. By substituting values of molar mass, density and how many electrons each atom allows to be free for other metals, you can find the free electron density for any metal. (a) The molar mass of copper is

63.5 \text{ gmole}^{-1}

. How many moles of copper atoms are there in 1 kg of copper? (b) Calculate how many atoms of copper there are in 1 kg. (Avogadro's number is

6.02 \times 10^{23} \text{ mole}^{-1}

.) (c) The density of copper is

8900 \text{ kg m}^{-3}

. Calculate how many atoms of copper there are in

1 \text{ m}^3

of copper. (d) If each atom of copper donates two electrons to the conduction band (in other words, there are two free electrons for each copper atom), calculate the free electron number density for copper.

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