Chapter 18.2, Problem 17SSC

Interpretation Introduction

Interpretation:

The contents of dilute solution of strong acid $HI$ and weak acid $HCOOH$ are to be decribed.

Concept introduction:

Strong acid dissociates completely in aqueous solution. But weak acid don’t dissociates completely.

Answer to Problem 17SSC

When $HI$ is dissolved in water, contents in solution are: $H_3{O}^{+}and{I}^{-}$

When $HCOOH$ is dissolved in water, contents in solution are: $HCOOH,H_3{O}^{+}andHCO{O}^{-}$

Explanation of Solution

When $HI$ is dissolved in water, the equation is given as:

$HI+H_{2}O\to I^{-}+H_3{O}^{+}$

$HI$ is strong acid so it is completely dissolved.

But $HCOOH$ is weak acid, it remains in equilibrium with dissociated ions on dissolution as:

$HCOOH+H_{2}O\rightleftharpoons HCO{O}^{-}+H_3{O}^{+}$

Conclusion

Thus, strong acids are completely dissociated but weak acids dissociated to a particular extent according to its strength.