The ionization constant of dimethylamine is $$5.4 \times 10^{-4}$$ Calculate its degree of ionization in its 0.02 M solution. What percentage of dimethylamine is ionized if the solution is also 0.1 M in NaOH?

Asked by Pragya Singh | 11 months ago |  138

#### 1 Answer

##### Solution :-

$$K_{b}=5.4\times 10^{-4}\\ \\$$

$$c=0.02M\\ \\$$

$$Then,\alpha$$

$$=\sqrt{\dfrac{K_{b}}{c}}\\ \\ =\sqrt{\dfrac{5.4\times 10^{-4}}{0.02}}=0.1643$$

Now, if 0.1 M of NaOH is added to the solution, then NaOH (being a strong base) undergoes complete ionization.

NaOH(aq) $$\leftrightarrow$$  Na+(aq)  +  OH(aq)

0.1M        0.1M

And,

(CH3)2 NH   +  H2$$\leftrightarrow$$ (CH3)2 NH2+  + OH

(0.02-x),     x,    x

0.02M        0.1M

Then,[ (CH3)2 NH+2] = x

[OH ] = x + 0.1;0.1

$$\Rightarrow K_{b}=\dfrac{[(CH_{3})_{2}NH_{2}^{+}][OH^{-}]}{[(CH_{3})_{2}NH]}\\$$

$$= 5.4\times 10^{-4}$$

$$=\dfrac{x\times 0.1}{0.02}\\ \\$$

$$x=0.0054$$

It means that in the presence of 0.1 M NaOH, 0.54% of dimethylamine will get dissociated.

Answered by Pragya Singh | 11 months ago

### Related Questions

#### The concentration of sulphide ion in 0.1M HCl solution saturated with hydrogen sulphide is 1.0 × 10–19 M.

The concentration of sulphide ion in 0.1M HCl solution saturated with hydrogen sulphide is 1.0 × 10–19 M. If 10 mL of this is added to 5 mL of 0.04M solution of the following: FeSO4, MnCl2, ZnCl2 and CdCl2 . in which of these solutions precipitation will take place?

Class 11 Chemistry Equilibrium View Answer

#### What is the minimum volume of water required to dissolve 1g of calcium sulphate at 298 K?

What is the minimum volume of water required to dissolve 1g of calcium sulphate at 298 K? (For calcium sulphate, Ksp is 9.1 × 10–6).

Class 11 Chemistry Equilibrium View Answer

#### What is the maximum concentration of equimolar solutions of ferrous sulphate and sodium sulphide

What is the maximum concentration of equimolar solutions of ferrous sulphate and sodium sulphide so that when mixed in equal volumes, there is no precipitation of iron sulphide? (For iron sulphide, Ksp = 6.3 × 10–18).

Class 11 Chemistry Equilibrium View Answer

#### The ionization constant of benzoic acid is 6.46 × 10–5 and Ksp for silver benzoate is 2.5 × 10–13.

The ionization constant of benzoic acid is 6.46 × 10–5 and Ksp for silver benzoate is 2.5 × 10–13. How many times is silver benzoate more soluble in a buffer of pH 3.19 compared to its solubility in pure water?

Class 11 Chemistry Equilibrium View Answer

#### Equal volumes of 0.002 M solutions of sodium iodate and cupric chlorate are mixed together.

Equal volumes of 0.002 M solutions of sodium iodate and cupric chlorate are mixed together. Will it lead to precipitation of copper iodate? (For cupric iodate Ksp = 7.4 × 10–8 ).

Class 11 Chemistry Equilibrium View Answer