For next buffer, pH should be closest to pKa of the acid.
So, pKa of the acid should be around 4.5
use:
pKa = -log Ka
4.5 = -log Ka
Ka = 3.16*10^-5
Ka value closest is for option 2
Answer: option 2
QUESTION 25 2.5 points Which acid, together with its sodium salt, would be best for preparing a buffer with a pH =...
Which weak acid would be best to use when preparing a buffer solution with a pH of 8.10? An acid with Ka = 5.0 × 10-10 An acid with Ka = 8.3 × 10-9 An acid with Ka = 1.6 × 10-5 An acid with Ka = 1.0 × 10-4 An acid with Ka = 1.3 × 10-6 An acid with Ka = 1.3 × 10-3
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7) Which one of the following is the weakest acid? A) HF (Ka = 6.8 × 10-4) B) HClO (Ka = 3.0 × 10-8) C) HNO2 (Ka = 4.5 × 10-4) D) HCN (Ka = 4.9 × 10-10) B) 5.7 x 10–2 M D) 2.9 x 10–3 M 22) Calculate the hydrogen ion concentration in a solution of iced tea with lemon having a pH of 2.87. A) 2.9x10–2M D) 2.9x10–3M B) 5.7 x 10–2 M E) 5.7 x 10–4...
Which of the following weak acids and is salt could you use to make a buffer solution with a pH of 3.00? acetic acid/sodium acetate Ka - 1.8 x 10-5 hydrocyanic acid/sodium cyanide Ka - 4.9 x 10-10 phosphoric acid/sodium dihydrogen phosphate Ka - 7.5 x 10-3 Carbonic acid/sodium bicarbonate Ka = 4.3 x 10?
Consider a 0.20 M solution of the salt, sodium cyanide, NaCN. A) What acid and What base reacted to from this salt? B) Classify the acid above as a strong or weal acid. Classify the base as a strong or weak base? C) Will the salt solution be acidic, basic, or neutural? D) Calculate the ph of the solution? The Ka of HCN is 4.9 x 10-10?
Preparing Buffer Solutions: Calculating the Number of Grams of Conjugate Base Needed Use the table of K values given with this problem to choose the best weak acid to start from for making a buffer that holds the pH of the solution at 8.50. Make your selection so that you maximize the capacity of the buffer. Weak Acid K 1.8 X 10-5 6.5 X 10-5 1.5 X 10-5 You select a 800.0 ml volumetric flask to which you add 8.00...
You work in a chemistry lab, and are asked to prepare 500 mL of a buffer solution with pH-3.20, The weak acid solution concentration in this buffer should be 0.250 M and salt is a solid. The following steps walk you through a step by step process of this preparation. a. Choose the proper weak acids for the buffer solution Table 1. Ionization constant Ka for some weak acids Name Hydrofluoric acid Nitrous acid Fulminic acid Acetic acid Hypochlorous acid...
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