Chapter 16.1, Problem 5RQ

Interpretation Introduction

Interpretation: To label which species acts as Brønsted-Lowry acid-base pair.

Concept introduction: A Brønsted-Lowry acid is a hydrogen ion ( $H^{+}$ ) donor. A Brønsted-Lowry base is a proton hydrogen ion ( $H^{+}$ ) acceptor.

A species that can as act both as an acid and as a base according to Brønsted-Lowry Theory is said to be amphoteric. Since water can act both as an acid and as a base, water is amphoteric.

Answer to Problem 5RQ

  $H_{2}O$ act as both acid and base.

Explanation of Solution

  

As, we can see from the reaction mechanism that one molecule of $H_{2}O$ accepts hydrogen (acting as an acid) from other $H_{2}O$ molecule which is acting as a base.

Conclusion

  $H_{2}O$ act as both acid and base.