Question

Write a balanced equation and ka expression for the bronsted-lowry acid hcooh in water

Answer 1

The given acid is HCOOH, it is dissociated in water. This balanced equation represents the dissociation of HCOOH in water:

HCOOH + H2O ---> H+ + COOH-

The Ka of HCOOH is:

Ka = concentration of products / concentration of reactants

Ka = [COOH-] [H+] / [HCOOH]

Answer 2

Balanced equation for dissociation of HCOOH in water is as follows:

$\boxed{\text{HCOOH}+\text{H}_2\text{O}\rightleftharpoons\text{HCOO}^{-}+\text{H}_3\text{O}^+}$

The expression for $\text{k}_\text{a}$ of HCOOH is as follows:

$\boxed{\text{k}_\text{a}=\dfrac{\text{[HCOO}^+[\text{H}^+]}{\text{[HCOOH]}}}$

Further Explanation:

ACIDS AND BASES:

These substances are defined by various concepts and theories from time to time. Some of these include their dissociation in water while others involve transference of some entities between the two.

(A) Arrhenius theory:

This theory involves donation of either hydrogen or hydroxide ions when there are present in solutions. So acids are substances that donate hydrogen ions $(\text{H}^+)$ in solutions and substances that are capable for donation of hydroxide ions $(\text{OH}^-)$ in solutions are bases.

(B) Bronsted-Lowry theory:

This theory describes acids as proton donors and bases act as proton gainers.

(C) Lewis theory:

In context of this theory for acid-base definition, acids refer to species that are capable to accept electrons from other species while bases are substances that have tendency to donate electron pairs.

The strength of acids is measured in terms of dissociation constant $(\text{k}_\text{a})$. Consider HX to be an acid whose dissociation occurs as follows:

$\text{HX}(aq)+\text{H}_2\text{O}(aq)\rightarrow\text{H}_3\text{O}^{+}(aq)+\text{X}^{-}(aq)$

The expression for dissociation constant of HX is as follows:

$\text{k}_\text{a}=\dfrac{[\text{X}^-][\text{H}_3\text{O}^+]}{[\text{HX}]}$

Where,

$\text{k}_\text{a}$ is dissociation constant of acid.

$[\text{H}_3\text{O}^+]$ is concentration of $\text{H}_3\text{O}^+$.

$[\text{X}^-]$ is concentration of $\text{X}^-$ ion.

[HX] is concentration of HX.

HCOOH is a weak acid. Hydrogen ion of HCOOH reacts with water molecule to form hydronium ion and as a result, $\text{HCOO}^-$ is also formed. HCOOH dissociates in water as follows:

$\text{HCOOH}+\text{H}_2\text{O}\rightleftharpoons\text{HCOO}^{-}+\text{H}_3\text{O}^+$

The expression for dissociation constant for the above reaction is as follows:

$\text{k}_\text{a}=\dfrac{[\text{HCOO}^-][\text{H}_3\text{O}^+]}{[\text{HCOOH}]}$

Learn more:

1. The reason for the acidity of water brainly.com/question/1550328

2. Reason for the acidic and basic nature of amino acid. brainly.com/question/5050077

Answer details:

Grade: High School

Subject: Chemistry

Chapter: Acid, base and salts

Keywords: acids, bases, HCOOH, H2O, H3O+, HCOO-, Arrhenius, Lewis, Bronsted-Lowry, ka, dissociation constant, hydrogen ion, hydronium ion, hydroxide ion.