Question

Silicon carbide (SiC) is made by the high-temperature reaction of silica sand (quartz) with coke; the byproduct is carbon monoxide.

(a) Write a balanced chemical equation for this reaction.

(b) Calculate the standard enthalpy change per mole of SiC produced.

(c) Predict (qualitatively) the following physical properties of silicon carbide: conductivity, melting point, and hardness.

Short answer

${\mathrm{SiO}}_2\left(\mathrm{s}\right)+3\mathrm{C}\left(\mathrm{s}\right)\to \mathrm{SiC}\left(\mathrm{s}\right)+2\mathrm{CO}\left(\mathrm{g}\right)$

Step-by-step solution

Subpart (a)Step 1: The given chemical reaction

In the given chemical reaction, the reactants are quartz ( ${\mathbf{SiO}}_2$ ) and coke.

The product is silicon carbide (SiC).

The word equation is as shown below:

$\mathrm{quartz}+\mathrm{coke}\to \mathrm{Silicon}\mathrm{carbide}$

The unbalanced chemical equation

The balanced chemical equation of the reaction is as shown below:

${\mathrm{SiO}}_2\left(\mathrm{s}\right)+\mathrm{C}\left(\mathrm{s}\right)\to \mathrm{SiC}\left(\mathrm{s}\right)+\mathrm{CO}\left(\mathrm{g}\right)$

The balanced chemical equation

The balanced chemical equation of the given reaction is as shown below:

${\mathrm{SiO}}_2\left(\mathrm{s}\right)+3\mathrm{C}\left(\mathrm{s}\right)\to \mathrm{SiC}\left(\mathrm{s}\right)+2\mathrm{CO}\left(\mathrm{g}\right)$