Calculating Coulombs for Chlorine Gas Production: A Chemistry Insight

Understanding the Basics of Electrolysis

So, you've got a problem: how many coulombs are needed to produce 18 cm³ of chlorine gas? Honestly, it's like being handed a puzzle that demands some fundamental chemistry skills to put together. Don’t worry, we’ll shine a light on the steps needed to crack this!

What’s the Big Deal About Chlorine Gas?

Chlorine gas (Cl0) is produced during the electrolysis of sodium chloride solution—a process that’s pretty crucial in both industrial and laboratory settings. And here’s a kicker: one mole of any gas at standard temperature and pressure (STP) fills about 24,000 cm³. Quite a generous amount, right?

Start with Mole Calculations

Let’s break it down a bit. To figure out how many moles exist in your 18 cm³ of chlorine gas, we can lay out a straightforward relationship:

[ \text{Moles of } Cl_2 = \frac{\text{Volume}}{\text{Molar Volume}} = \frac{18 \text{ cm}^3}{24000 \text{ cm}^3/\text{mol}} = 0.00075 \text{ mol}
]

Now, what does that number even mean? It tells us that in our 18 cm³ of chlorine gas, we have 0.00075 moles of Cl(_2). Not too shabby! But there’s more to explore.

Let’s Talk Electrons

Did you know that for every mole of chlorine gas produced, you need the transfer of 2 moles of electrons? That’s according to our good buddy, the half-reaction equation:

[
2 , Cl^- \rightarrow Cl_2 + 2e^-
]

So, if one mole requires 2 moles of electrons, how many moles do we need for our 0.00075 moles of chlorine gas?

[
\text{Electrons needed} = 0.00075 , \text{mol} \times 2 = 0.0015 , \text{mol} ]

Getting to the Charge

We’re almost there, I promise! The final piece of the puzzle is converting moles of electrons to coulombs. One mole of electrons carries approximately 96500 coulombs (C). Can you see where we’re headed?

[
\text{Coulombs needed} = 0.0015 , \text{mol} \times 96500 , \text{C/mol} \approx 144.45 , \text{C}
]

And there you have it! To produce 18 cm³ of chlorine gas, we indeed need about 144.45 coulombs. Makes sense?

Final Thoughts

As you advance in your chemistry studies, mastering calculations like this one can give you a significant confidence boost. Electrolysis is not merely a dry concept in textbooks; it’s a gateway to understanding how crucial chemical reactions work in real life—be it in swimming pools, manufacturing, or even treating water!

Next time you come across an electrolysis problem, remember this hands-on approach, and watch those complicated numbers start to make sense. Learning IGCSE Chemistry can feel overwhelming, but with each calculation, you’re building the foundations of your scientific understanding. Who knew chemistry could spark such light?

That’s the power of knowledge—keep questioning, keep calculating, and most importantly, keep being curious!