Which of the following is the STRONGEST
acid?
1. CH3COOH
2. CH3CH2OH
3. CHCl2COOH
4. CH2ClCOOH
5. CCl3COOH
#5 is a quite strong "weak" acid. The pKa value is about 0.7. All of the other acids listed are weaker.
To determine which of the given substances is the strongest acid, we need to consider their chemical properties.
Acids are characterized by their ability to donate a hydrogen ion (H+) in an aqueous solution. The strength of an acid depends on the stability of the resulting conjugate base after it donates the H+ ion.
Here's how you can compare the strengths of the given acids:
1. CH3COOH (acetic acid): Acetic acid is a weak acid. It can donate a hydrogen ion (H+) but does not completely dissociate in water.
2. CH3CH2OH (ethanol): Ethanol is not an acid; it is an alcohol and does not donate H+ ions.
3. CHCl2COOH (dichloroacetic acid): Dichloroacetic acid is stronger than acetic acid because the presence of two chlorine atoms increases the electronegativity and thus the acidity.
4. CH2ClCOOH (monochloroacetic acid): Monochloroacetic acid is weaker than both acetic acid and dichloroacetic acid because it has a single chlorine atom.
5. CCl3COOH (trichloroacetic acid): Trichloroacetic acid is the strongest acid among the options given. It has three chlorine atoms, which increases the acidity even further.
Therefore, the answer is option 5. CCl3COOH (trichloroacetic acid) is the strongest acid among the given choices.
To determine the strongest acid among the given options, we need to consider the acidity of the compounds. Acidity is generally determined by the ability of a molecule to donate protons (H+ ions). The more readily a compound donates protons, the stronger the acid it is.
Among the options given, the strength of acids can be compared based on the number of electronegative atoms attached to the central carbon in the molecule. Acids with more electronegative atoms are generally stronger.
Let's analyze the given options:
1. CH3COOH (acetic acid): It has one electronegative oxygen attached to the central carbon.
2. CH3CH2OH (ethanol): Ethanol is not an acid but an alcohol, so it does not donate protons.
3. CHCl2COOH (dichloroacetic acid): It has two electronegative chlorine atoms attached to the central carbon.
4. CH2ClCOOH (monochloroacetic acid): It has one electronegative chlorine atom attached to the central carbon.
5. CCl3COOH (trichloroacetic acid): It has three electronegative chlorine atoms attached to the central carbon.
Among the options provided, CCl3COOH (trichloroacetic acid) has the highest number of electronegative atoms attached to the central carbon, making it the strongest acid among the given compounds.
Therefore, the strongest acid among the options provided is CCl3COOH (trichloroacetic acid).