Acid series · lab

Buffer Lab: watch the protons move.

A live weak acid. At its pK_a it is half acid, half base, and each pH unit up multiplies the base-to-acid ratio by ten. Titrate it with NaOH and the curve, the numbers and the molecules move together.

CH₃COOHCH₃COO⁻ In view: 22 CH₃COO⁻ and 22 CH₃COOH

pH: 4.76= pK_a
[A⁻]/[HA]: 1.00= 10^0.00
Deprotonated: 50.0%as CH₃COO⁻
pK_a: 4.76acetic acid

pH = pK_a + log([A⁻]/[HA])4.76 = 4.76 + log(1.00)

pH4.76

Predict first

Acid

Acetic acidCH₃COOH4.76 Carbonic acidCO₂/HCO₃⁻, blood6.1 Dihydrogen phosphateH₂PO₄⁻7.2 AmmoniumNH₄⁺9.25 Your ownany pK_a from 4 to 105.00

Practice it in the course

Watch the Acid series100 billion times more acidic than ethanol, 20 bicarbonates per CO₂, pH = pK_a halfway Check yourself on the acid series60 seconds, answers included Red Pen Prep homeThe course, the trap diagnostic and the other labs

Now one question on it

Same idea, from the course.

From the coursefrom the course, Chem/Phys

A buffer is made from a weak acid with pKa 6.8 and its conjugate base. At pH 7.8, what is the ratio [base]/[acid]?

Pick one. The red pen does the rest.

This is 1 of 3,122 questions in the Pass, all corrected like this one.

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