DE Unit 9 (AB Reactions) Review Quizizz

A solution of 6.5 M HF (Ka = 6.6x10^-4) is added to 0.10 LiF. What is the pH of the solution?

• 3.18

• 1.36

• 5.6

• 1.4

What is the pH of a 0.75 M HF solution? What is the pH when the HF is in 0.15 M HCl? K_a for HF = 6.8x10^-4

• 0.12, 0.82

• 0.12, 0.22

• 1.65, 2.47

• 1.65, 0.8

Buffer is defined as

• ability to resist pH change for any amount of acid or base added

• ability to prevent pH from decreasing
• ability to resist a pH increase
• ability to resist pH change when small amount of acid or base added

Which of the following combinations is not suitable for making a buffer?

• HClO₄ and NaClO₄

• H₂CO₃ and NaHCO₃

• NH₄Cl and NH₃

• H₃PO₄ and NaH₂PO₄

Acidic buffer is made up of

• weak acid and weak base
• weak acid and its conjugate salt
• weak acid and its conjugate base
• strong acid and its conjugate base

In a buffer solution of HF and NaF, which would neutralize the addition of a small quantity of HCl?

• F^-

• HF

• OH^-

• H⁺

What is the pH of a buffer made by combining 181 mL of 0.34 M NaC₂H₃O₂ with 170 mL of 0.28 M HC₂H₃O₂? The K_a of acetic acid is 1.75 × 10^-5.

• 4.88

• 4.64

• 5.93

• 4.81

How many grams of sodium formate (NaCHO₂) must be added to 100 mL to create a buffer with 0.200 M formic acid (HCHO₂) to make a solution with pH = 3.50. K_a for formic acid is 1.7x10^-4

• 0.82 grams

• 0.73 grams

• 0.60 gram

• 12.1 grams

If a given salt dissociates and forms a strong base and a weak acid, the salt is considered to be ____

• acidic

• basic

• neutral

What will this salt be? CaCO₃

• acidic

• basic

• neutral