Chapter 8, Problem 25A

Interpretation Introduction

Interpretation : The element that loses electron and the element that gains electron are to be stated when sodium reacts with non-metal that is sulphur.

Concept Introduction : The reaction between metal and non-metal involves ionic bond. In a chemical compound, the positively charged species is termed as cation, whereas the negatively charged species is termed as anion.

Answer to Problem 25A

In the reaction of sodium and sulfur, sodium loses electron, whereas sulfur gains electrons.

Explanation of Solution

The reaction between metal and non-metal leads to the formation of ionic bond. A reaction between sodium and sulfur is as follows.

  $\text{2Na}\left(\text{s}\right)+\text{S}\left(\text{s}\right)\to {\text{Na}}_{\text{2}}\text{S}\left(\text{s}\right)$

The above equation can be written as,

  $\begin{array}{c}\text{Na}\to {\text{Na}}^{+}+{\text{e}}^{-}\\ \text{S}+2{\text{e}}^{-}\to {\text{S}}^{2-}\end{array}$

From the above reaction, it is clear that sulfur atom gains two electrons to form negatively charged ion that is sulphide ion, while sodium loses electron to form a positively charged ion that is sodium ion.

Conclusion

In the reaction of sodium and sulfur, sodium loses electron, whereas sulfur gains electrons.