1. Compare based on Ka: a. what is the Ka of H2PO4- and NH4+ when they functions

Question

1. Compare based on Ka:

a. what is the Ka of H2PO4- and NH4+ when they functions as acids?

b. Which one is a stronger acid based Ka comparison?

2. Considering the amphoteric behavior of H2PO4-, the above comparison may or may not correct. Instead, let us compare based on pH of these two at the same concentration. Do not forget the amphoteric behavior of H2PO4-:

a. What is the pH of 0.1 M H2PO4- (for example, 0.1 M NaH2PO4)?

b. What is the pH of 0.1 M NH4+ (for example, 0.1 M NH4Cl)?

c. Which one is more acidic?

d. Does pH of NaH2PO4 change if its concentration changes? How about NH4Cl?

e. At what concentration NH4Cl will have the same pH as NaH2PO4? is this concentration realistic?

f. Based on pH calculation, which one is more acidic, H2PO4- or NH4+?

Explanation / Answer

1.

a.)

Ka of H2PO4- = 6.2 x 10^-8

Ka of NH4+ = 5.56 x 10^-10

here H2PO4- is high value of Ka than NH4+. so H2PO4- is strong acid than NH4+

b)

H2PO4- is strong acid

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.