Calculate the ph of a buffer that is 0.020 m hf and 0.040 m naf. the ka for hf is 3.5 × 10-4.

Calculate the ph of a buffer that is 0.020 m hf and 0.040 m naf. the ka for hf is 3.5 × 10-4.

Answers

 pH = pKa + log ([base]/[acid]) = -log (3.5 x 10^-4) + log (0.040/.020) = 3.46 - 0.30 = 3.16

The given buffer solution is 0.020 M HF and 0.040 M NaF.

Given the K_{a} of HF is 3.5 * 10^{-4}

Finding out pK_{a}:

pK_{a} = -logK_{a}

= - log(3.5 * 10^{-4})

= 3.46

We use the Hendersen-Hasselbalch equation to find out the pH of a buffer solution:

pH = pK_{a} + logfrac{[Base]}{[Acid]}

[Base] =[NaF] = 0.040 M

[Acid] = [HF] =0.020 M

Plugging in the values to find out pH,

pH = 3.46 + logfrac{0.040}{0.020}

pH = 3.46 + log(2)

= 3.76

Therefore, pH of the buffer is 3.76

The correct answer is c

the answer to your question is c

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