Explanation:
The given reaction is as follows.
Hence, number of moles of NaOH are as follows.
n = 
= 0.005 mol
After the addition of 25 ml of base, the pH of a solution is 3.62. Hence, moles of NaOH is 25 ml base are as follows.
n = 
= 0.0025 mol
According to ICE table,
Initial: 0.005 mol 0.0025 mol 0 0
Change: -0.0025 mol -0.0025 mol +0.0025 mol
Equibm: 0.0025 mol 0 0.0025 mol
Hence, concentrations of HA and NaA are calculated as follows.
[HA] = 
[NaA] =
![[A^{-}] = [NaA] = \frac{0.0025 mol}{V}](https://tex.z-dn.net/?f=%5BA%5E%7B-%7D%5D%20%3D%20%5BNaA%5D%20%3D%20%5Cfrac%7B0.0025%20mol%7D%7BV%7D)
Now, we will calculate the 
value as follows.
pH = 
![pK_{a} = pH - log \frac{[A^{-}]}{[HA]}](https://tex.z-dn.net/?f=pK_%7Ba%7D%20%3D%20pH%20-%20log%20%5Cfrac%7B%5BA%5E%7B-%7D%5D%7D%7B%5BHA%5D%7D)
= 
= 3.42
Thus, we can conclude that of the weak acid is 3.42.
The relative volumes of chloroform and water that should be used is 9:10
Concentration of solution in chloroform = 
( moles of chloroform )
Concentration of solution in water = 
( moles of water )
Dissociation constant at 
; 
Concentration of solution in chloroform / Concentration of solution in water
Meaning;
Since mole is present in chloroform and mole is present in water, Total mole of Caffeine present is 
Now, we substitute our given values into the equation
Therefore, the relative volumes of chloroform and water that should be used is 9:10
Learn more; brainly.com/question/11060225
<span>The correct answer is 'freezing point depression'. Colligative properties depend on the concentration of molecules of a solute. Examples of other colligative properties are boiling point elevation or vapour pressure lowering. The salt causes ice on the side walk to melt because it lowers the freezing point. </span>
Answer:
3 × 10^8 m/s
Explanation:
The wavelength, can be calculated by using the following formula;
λ = v/f
Where;
λ = wavelength (m)
v = velocity/speed of light (m/s)
f = frequency (Hz)
According to the provided information in this question, λ = 600nm i.e. 600 × 10^-9m, f = 5.00 x 10^14 Hz
Hence, using λ = v/f
v = λ × f
v = 600 × 10^-9 × 5.00 x 10^14
v = 6 × 10^-7 × 5.00 x 10^14
v = 30 × 10^(-7 + 14)
v = 30 × 10^ (7)
v = 3 × 10^8 m/s
Answer:
Ka = 1.52 E-5
Explanation:
- CH3-(CH2)2-COOH ↔ CH3(CH2)2COO- + H3O+
⇒ Ka = [H3O+][CH3)CH2)2COO-] / [CH3(CH2)2COOH]
mass balance:
⇒<em> C</em> CH3(CH2)2COOH = [CH3(CH2)2COO-] + [CH3(CH2)2COOH] = 1.0 M
charge balance:
⇒ [H3O+] = [CH3(CH2)2COO-]
⇒ Ka = [H3O+]²/(1 - [H3O+])
∴ pH = 2.41 = - Log [H3O+]
⇒ [H3O+] = 3.89 E-3 M
⇒ Ka = (3.89 E-3)² / ( 1 - 3.89 E-3 )
⇒ Ka = 1.519 E-5
