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Rocket

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

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Atom Symbol

Chapter 1 - Models Of The Particulate Nature Of Matter

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Chapter 2 - Models Of Bonding & Structure

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 Globe with Meridians

Chapter 3 - Classification Of Matter

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Fire

Chapter 4 - What Drives Chemical Reactions?

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Test Tube

Chapter 6 - What Are The Mechanisms Of Chemical Change?

<ul>
	<li>Rate of a reaction indicates how fast it proceeds.</li>
	<li>Reaction rates are affected by the concentration of reactants.</li>
</ul>

🔍 Real-World Example: Imagine a dance floor. More dancers (reactants) mean more potential dance partners. The more dancers, the quicker the dance floor gets filled (faster reaction).

<ul>
	<li>If the concentration of a reactant increases, the reaction rate might increase.</li>
	<li>For the general reaction:&nbsp; A + B &rarr; C, the rate (&nu;) can be related to concentrations
	<ul>
		<li>&nu; &prop; [A]n</li>
		<li>&nu; &prop; [B]m</li>
	</ul>
	</li>
	<li>Here, n and m can be 0, 1, or 2.</li>
</ul>

🔍 Real-World Example: Think of n and m as volume knobs for speakers A and B. Turning the knob (changing concentration) might increase or decrease the sound (reaction rate).

<ul>
	<li>Combining the relationships, we get:&nbsp;&nu; = k [A]n[B]m</li>
	<li>Here, k is the rate constant.</li>
	<li>n and m, called reaction orders, show how the concentration of reactants A and B affects the rate.</li>
	<li>n + m = overall reaction order.</li>
</ul>

<ul>
	<li>Indicated using square brackets: e.g., [A].</li>
	<li>The expression [A]n is shorthand for concentration of A raised to the power n.</li>
</ul>

<ul>
	<li>At low temperatures
	<ul>
		<li>Reaction rate depends on collisions between NO2 molecules: &nu; = k[NO2]2</li>
		<li>Order: NO2 (2nd order), CO (0th order). Overall: 2nd order.</li>
	</ul>
	</li>
	<li>At high temperatures
	<ul>
		<li>Reaction rate depends on collisions between NO2 and CO molecules: &nu; = k[NO2][CO]</li>
		<li>Order: NO2 and CO both 1st order. Overall: 2nd order.</li>
	</ul>
	</li>
</ul>

🔍 Real-World Example: Like making hot chocolate on a cold day vs. a warm day. On cold days, you might stir it slowly (one step) while on warm days, you stir quickly (different steps). The end result (hot chocolate) is the same, but the process and speed might differ!

<ul>
	<li>To know if a reaction is 1st, 2nd, or 0th order for a particular reactant, we conduct experiments.</li>
	<li>For a hypothetical reaction&nbsp; A +B + C &rarr;D:
	<ul>
		<li>If doubling A doubles the rate, it&#39;s 1st order for A.</li>
		<li>If doubling B quadruples the rate, it&#39;s 2nd order for B.</li>
		<li>If doubling C doesn&rsquo;t change the rate, it&#39;s 0th order for C.</li>
	</ul>
	</li>
</ul>

🔍 Real-World Example: Consider building a LEGO tower. If adding more blue LEGO bricks (A) doubles the tower&#39;s height, but adding more red LEGO bricks (B) quadruples it, while adding green LEGO bricks (C) doesn&#39;t change it, you&#39;ll know how each LEGO brick type influences the tower height.

Based on the given data

<ul>
	<li>Reaction is 1st order with respect to Fe3+.</li>
	<li>Reaction is 2nd order with respect to I-.</li>
	<li>Rate equation:&nbsp; &nu; = k[Fe3+][I&minus;]2</li>
	<li>Overall reaction order: 3</li>
</ul>

<ul>
	<li>Reactions can also be studied using graphical methods.</li>
	<li>Zero-order: Flat horizontal line.</li>
	<li>First-order: Straight line from origin.</li>
	<li>Second-order: Parabolic curve.</li>
</ul>

🔍 Real-World Example: Imagine tracking the speed of a car. A constant speed is like a zero-order reaction (a straight, flat path). A steadily increasing speed is like a first-order reaction (a straight uphill road). A speed that increases faster as time goes on is like a second-order reaction (a curving uphill road).

Always remember, these reaction orders can&#39;t be guessed from just looking at the reaction, they are determined experimentally! Also, temperature is a sneaky factor; it can change the rate constant, so experiments should be at a constant temperature!

&nbsp;

Happy studying! 📚🔬

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

Unlock Rate Equations: Reactivity Guide 2.2.9

Table of content

Basics of Rate Equations

Rate and Concentration

The Rate Equation

Molar Concentrations

Unlock the Full Content!

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

Unlock Rate Equations: Reactivity Guide 2.2.9

Table of content

Basics of Rate Equations

Rate and Concentration

The Rate Equation

Molar Concentrations

Unlock the Full Content!