pKA and Ka of an acid check for understanding quiz

Calculate the acid dissociation constant, K_a, at 298 K for a 0.20 mol dm^-3 solution of propanoic acid with a pH of 4.88.

• • K_a = 8.70 × 10^-10

• • K_a = 8.70 × 10^-5

• • K_a = 1.32 × 10^-5

• • K_a = 4.88 × 10^-10

Which of the following is the acid dissociaiton, Ka, constant for ethanoic acid (CH3COOH)?

• CH3COOH

• 
• 
• 

At the same concentration, which acid would have the lowest pH?

• 
• 
• 
• 

• 4.95

• 2.47

• 0.12

• 4.82

Which of the following is the correct order of increasing strength of the acids?

• Phenol < butanoic acid < lactic acid < nitrous acid

• Phenol < lactic acid < butanoic acid < nitrous acid

• Nitrous acid < lactic acid < butanoic acid< phenol

• Nitrous acid < butanoic acid < phenol < lactic acid