test-tube.png

Test Tube

Chapter 6 - What Are The Mechanisms Of Chemical Change?

atom-symbol.png

Atom Symbol

Chapter 1 - Models Of The Particulate Nature Of Matter

dna.png

Chapter 2 - Models Of Bonding & Structure

globe-with-meridians.png

 Globe with Meridians

Chapter 3 - Classification Of Matter

fire.png

Fire

Chapter 4 - What Drives Chemical Reactions?

rocket.png

Rocket

Chapter 5 - How Much, How Fast & How Far?

Imagine you&#39;re throwing a party 🎉. Too much hype, and it becomes a riot; too quiet, and it&#39;s a snooze fest. You need that balance! In chemistry, buffers are like the DJs of solutions&mdash;they keep the pH level just right. And today, we&#39;re going to look at the math behind it, through the eyes of our VIP guest, the Henderson&ndash;Hasselbalch equation. 🎶

<ul>
	<li>Buffer Solution: A solution that resists changes in pH when acid or base is added.</li>
	<li>Conjugate Acid-Base Pair: Two substances that transform into each other by gaining or losing a proton (H+).</li>
	<li>Ka: Acid dissociation constant.</li>
	<li>Henderson&ndash;Hasselbalch Equation: Calculates the pH of a buffer solution.</li>
</ul>

<ul>
	<li>
	Acid-Base Equilibrium

	<ul>
		<li>Weak Acid (HA) + Water ⇌ H⁺ + Conjugate Base (A⁻)</li>
		<li>Ka = [H+][A&minus;] / [HA]</li>
	</ul>
	</li>
	<li>
	Calculate H⁺ ion concentration

	<ul>
		<li>[H+] = Ka &times; \(\frac {[HA]}{[A^-]}\)</li>
	</ul>
	</li>
	<li>
	From H⁺ to pH (Henderson&ndash;Hasselbalch)

	<ul>
		<li>pH = pKa + log\(\frac {[A^-]}{[HA]}\)</li>
	</ul>
	</li>
</ul>

🍋 Real-World Examples

<ul>
	<li>Blood pH: Ever wonder how our blood maintains a steady pH level around 7.4? Yep, it&#39;s buffered!</li>
</ul>

<ul>
	<li>Dilution doesn&#39;t affect buffer pH: Like diluting a cordial, but the taste remains the same!</li>
	<li>Infinite dilution leads to pH 7.00: Imagine diluting a can of soda until it tastes like plain water.</li>
	<li>Limited Capacity: A buffer isn&#39;t a superhero. It runs out of &quot;buffering power&quot; if you add too much acid or base.</li>
</ul>

Worked Example 10: Calculate the pH of an ethanoate buffer

<ul>
	<li>Given

	<ul>
		<li>Acid = CH3COOH: 0.100&thinsp;moldm&minus;30.100moldm&minus;3</li>
		<li>Base = CH3COO⁻: 0.200&thinsp;moldm&minus;30.200moldm&minus;3</li>
		<li>pKa (CH3COOH) = 4.76</li>
	</ul>
	</li>
	<li>Use Henderson&ndash;Hasselbalch
	<ul>
		<li>pH = 4.76 + log&nbsp;\(\frac {0.200}{0.100} = 5.06\)</li>
	</ul>
	</li>
</ul>

🍎 Think of it like a recipe. Too much vinegar in your vinaigrette? The pH tells you if it&#39;s balanced!

Worked Example 11: Methylamine Buffer with pH 11.00

<ul>
	<li>Conjugate Acid-Base Pair: CH3NH3+ (acid) &amp; CH3NH2 (base)</li>
	<li>Reactant in Excess: Methylamine, because it&#39;s our buffer&rsquo;s backbone.</li>
	<li>Mole Ratio: pKa (CH3NH3+) =10.66
	<ul>
		<li>11.00 = 10.66 +log&nbsp;\(\frac {[CH3NH2]}{[CH3NH3^+]}\)</li>
		<li>Mole ratio&nbsp; CH3NH3+&nbsp;: CH3NH2 = 1:2.19</li>
	</ul>
	</li>
</ul>

🚗 Imagine a car with an almost empty gas tank (limited acid) and a full tank (limited base). You can&#39;t go far without refilling one of them, just like a buffer can&#39;t go far without its components!

&nbsp;

And that&#39;s a wrap! 🎬 With this knowledge, you can be the DJ of the chemistry world, maintaining that pH &#39;beat&#39; just right.

&nbsp;

Happy Studying! 📚

Unlock The Secrets of Buffer Solution pH!

ib-higher-level.webp

Higher Level

Chemistry HL

Chapter 6 - What Are The Mechanisms Of Chemical Change?

Unlock The Secrets of Buffer Solution pH!

Table of content

Intro - What's a Buffer? 🌈

Key Concepts 🎯

The Mathy Part: Equations 🤓

Unlock the Full Content!

Chapter 6 - What Are The Mechanisms Of Chemical Change?

Unlock The Secrets of Buffer Solution pH!

Table of content

Intro - What's a Buffer? 🌈

Key Concepts 🎯

The Mathy Part: Equations 🤓

Unlock the Full Content!