*PHYSICAL PROPERTIES OF ORGANIC COMPOUNDS (SERIES 2)*

Which are the correct order of increasing acidity for the following compound?

Water, Ethanol, Phenol

• Water < Ethanol < Phenol

• Phenol < Ethanol < Water

• Ethanol < Water < Phenol

• Water < Phenol < Ethanol

Which carboxylic acid is most acidic?

• CH₃CH₂CH₂COOH

• CH₃CH₂CH(Cl)COOH

• CH₃CH(Cl)CH₂COOH

• ClCH₂CH₂CH₂COOH

In acidicity, phenol release proton to water produce:

• Carboxylate ion

• Phenoxide ion

• Alkoxide ion

• Phenolate ion

Choose INCORRECT statement why phenol is more acidic than ethanol

• negative charge of ethoxide ion is localised on oxygen atom

• phenoxide ion is stable than ethoxide ion

• Present of electron donating group of phenol

• Negative charge of phenoxide ion can be delocalised into benzene ring

Which of the following compound is expected to be most basic?

• Aniline

• Ammonia

• p-nitroaniline

• Ethylamine

By the presence of a halogen atom in the chain, what is the effect of this on acidic properties of butanoic acid?

• Increased

• Decreased

• Unchanged

• Doubled

The correct order of increasing basic strength is

• Aniline < p-nitroaniline < NH₃ < CH₃NH₂

• Aniline < p-nitroaniline < CH₃NH₂ < NH₃

• p-nitroaniline < aniline < NH₃ < CH₃NH₂

• p-nitroaniline < aniline < CH₃NH₂ < NH₃

Which of the following lists the compounds in increasing order of acidity?

S: C₆H₅OH

T: CH₃CH₂OH

U: CH₃COOH

V: CH₂ClCOOH

• S < T < U < V

• T < S < U < V

• S < T < V < U

• T < S < V < U

Which of the following shows the correct order of increasing basic strength?

X: C₆H₅NH₂

Y: CH₃CH₂NH₂

Z: CH₃CH₂NHCH₃

• X < Y < Z

• X < Z < Y

• Y < X < Z

• Z < Y < X

The pKa of methanoic acid and ethanoic acid are 3.74 and 4.74 respectively. This means that;

• Methanoic acid is stronger acid than ethanoic acid

• Methanoic acid is weaker acid than ethanoic acid

• Ethanoate ion is a weaker conjugate base than methanoate ion

• Degree of dissociation of methanoic acid is lower than ethanoic acid