What is the Ka of maleic acid?
What is the Ka of maleic acid?
E5: Acid Dissociation Constants of Organics
| Compound | Conjugate Acid | pKa |
|---|---|---|
| lysine (μ = 0.1 M) | 2.04 (COOH) 9.08 (α-NH3) 10.69 (ε-NH3) | |
| maleic acid | 1.910 6.332 | |
| malic acid | 3.459 (COOH) 5.097 (COOH) | |
| malonic acid | HOOCCH2COOH | 2.847 5.696 |
What is the dissociation constant K for an acid?
Acid dissociation constant (Ka) is used to quantitatively measure the strength of an acid. Acid dissociation constant is nothing but the equilibrium constant calculated for the ionisation of an acid. An acid HA dissociates into the hydrogen ion (H+) and the conjugate base of that acid (A-).
How do you find the acid dissociation constant?
1 Answer
- Write the equation for the dissociation of a generic monoprotic acid: HA + H₂O ⇌ H₃O⁺ + A⁻
- Write the dissociation constant expression. Ka=[H₃O⁺][A⁻][HA]
- Determine the equilibrium concentrations. pH = -log[H₃O⁺] = 4.69.
- Substitute these values in the expression and that is it!
What is the equilibrium constant for the complete dissociation of Malonic acid?
The dissociation constants found for malonic acid at 25° C are K, = 2.06XlO-3 and K2 = 2.94X IO-6.
What is the pKa of maleic acid?
1.83
Properties
| Property | Value | Source |
|---|---|---|
| melting point (°C) | 130.5 °C | PhysProp |
| water solubility | 4.41E+005 mg/L (at 25 °C) | YALKOWSKY,SH & DANNENFELSER,RM (1992) |
| logP | -0.48 | SANGSTER (1994) |
| pKa | 1.83 | LIDE,DR (1996) |
What is the pKa of malic acid?
For malic acid, the pka values are 3.4 and 5.2 and for tartaric acid, the pka values are 2.95 and 4.25.
What is Ka value of an acid?
The Ka value is found by looking at the equilibrium constant for the dissociation of the acid. The higher the Ka, the more the acid dissociates. Thus, strong acids must dissociate more in water. In contrast, a weak acid is less likely to ionize and release a hydrogen ion, thus resulting in a less acidic solution.
What is the value of Ka?
A small Ka value means little of the acid dissociates, so you have a weak acid. The Ka value for most weak acids ranges from 10-2 to 10-14.
Which is more stable maleic or fumaric acid?
Fumaric acid being the trans isomer will have the least steric hindrance as the carboxylic acid groups will be on the different sides of the double bonds causing the least electronic repulsion. Hence will be more stable as compared to Maleic acid.
