Question

Write the ka expression for ch3nh3 in water. click in the answer box to activate the palette.

Answer 1

Ka expression for methanaminium (CH3NH3+) is given as follow,

Answer 2

The expression for dissociation constant $\left( {{{\text{k}}_{\text{a}}}} \right)$ of ${\text{C}}{{\text{H}}_{\text{3}}}{\text{NH}}_3^ +$  in water is given as follows:

$\boxed{{{\text{k}}_{\text{a}}} = \frac{{\left[ {{\text{C}}{{\text{H}}_{\text{3}}}{\text{N}}{{\text{H}}_{\text{2}}}} \right]\left[ {{{\text{H}}_{\text{3}}}{{\text{O}}^ + }} \right]}}{{\left[ {{\text{C}}{{\text{H}}_3}{\text{NH}}_3^ + } \right]}}}$

Further Explanation:

ACIDS AND BASES:

Following theories are put forward from time to time so as these two terms can be defined.

Arrhenius theory:

According to this concept, acids donate hydrogen ions in solutions and bases donate hydroxide ions in solutions.

Bronsted-Lowry theory:

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

Lewis theory:

Acids are species that are capable to accept electrons from other species while bases are those having tendency to donate electron pairs.

Acid strength is measured with a term called as dissociation constant. It is denoted by ${{\text{k}}_{\text{a}}}$.

The chemical reaction between ${\text{C}}{{\text{H}}_{\text{3}}}{\text{NH}}_3^ +$ and water is as follows:

${\text{C}}{{\text{H}}_{\text{3}}}{\text{NH}}_3^ + + {{\text{H}}_{\text{2}}}{\text{O}} \rightleftharpoons {\text{C}}{{\text{H}}_3}{\text{N}}{{\text{H}}_{\text{2}}} + {{\text{H}}_{\text{3}}}{{\text{O}}^ + }$  

The expression for dissociation constant of ${\text{C}}{{\text{H}}_{\text{3}}}{\text{NH}}_3^ +$ is as follows:

${{\text{k}}_{\text{a}}} = \dfrac{{\left[ {{\text{C}}{{\text{H}}_{\text{3}}}{\text{N}}{{\text{H}}_{\text{2}}}} \right]\left[ {{{\text{H}}_{\text{3}}}{{\text{O}}^ + }} \right]}}{{\left[ {{\text{C}}{{\text{H}}_3}{\text{NH}}_3^ + } \right]}}$  

Where,

$\left[ {{\text{C}}{{\text{H}}_{\text{3}}}{\text{N}}{{\text{H}}_{\text{2}}}} \right]$  is the concentration of ${\text{C}}{{\text{H}}_{\text{3}}}{\text{N}}{{\text{H}}_{\text{2}}}$.

$\left[ {{\text{C}}{{\text{H}}_{\text{3}}}{\text{NH}}_3^ + } \right]$  is the concentration of ${\text{C}}{{\text{H}}_{\text{3}}}{\text{NH}}_3^ +$.

$\left[ {{{\text{H}}_3}{{\text{O}}^ + }} \right]$  is the concentration of ${{\text{H}}_{\text{3}}}{{\text{O}}^ + }$ .

Learn more:

1. The reason for the acidity of water https://brainly.com/question/1550328  
2. Reason for the acidic and basic nature of amino acid. https://brainly.com/question/5050077  

Answer details:  

Grade: High School  

Subject: Chemistry  

Chapter: Acid, base and salts  

Keywords: acids, bases, CH3NH3+, CH3NH2, H2O, H3O+, Arrhenius, Lewis, Bronsted-Lowry, concentration, [CH3NH3+], [CH3NH2], [H3O+], dissociation constant, hydrogen ion, hydroxide ion, dissociation constant, ka, expression, chemical reaction.