Think You Know Gas Laws? This Is A Real Stumper about Which Change Doesn't Raise Pressure!

Gas laws can leave you flustered, right? Let's tackle this: Which change doesn't raise pressure? It's not just about what increases, but what doesn't—in Boyle's Law terms. Temperature, volume decrease, adding gas all push pressure up, EXCEPT one...

Okay, let's dive into the fascinating world of gases and the laws that describe their behaviour! It's something we encounter every day, sometimes without even realizing it. From the way a scuba tank provides varying pressure underwater, to understanding why a tire is inflated just right, getting a handle on gas laws is essential.

Here’s a question to test your understanding of pressure changes in gas systems:

"Which of the following changes to a system will NOT result in an increase in pressure?"

Here are the options:

A. Raising the temperature

B. Decreasing the volume of the container

C. Adding more gas molecules

D. Increasing the volume of the container

(Think about this, give it a shot! I'll provide the explanation shortly.)


(Okay, okay, let's talk about pressure. We mean absolute pressure, folks - not relative to a vacuum or anything clever, just the direct force pushing outwards from the gas or, say, the pressure we measure with a tire gauge. Got it.)

Alright, now for the breakdown:

(You're probably wondering why the others are so tricky, right? They stick out like a safety pin in a haystack of pressure changes.)

First up: Raising the temperature. Temperature and pressure have a serious, direct relationship in most common scenarios, primarily defined by Gay-Lussac's Law (or sometimes informally, just the basic gas law connection). Think of it this way – if you've ever left a basketball in the hot sun, it might feel a little firmer. That's because the air inside heats up, its molecules move faster, bang into the wall with more speed and more frequency, and so the pressure inside the ball increases. So, raising the temperature absolutely does increase pressure (for a given amount of gas in a closed system). Option A is definitely out as the non-increaser we're looking for. Case closed, unless we're dealing with some ultra-low temperatures and quantum weirdness, but we're not!

Next, B. Decreasing the volume of the container. This one calls back to Boyle's Law – the classic inverse relationship between pressure and volume. Imagine squeezing that same basketball in your hand – forcing its volume down makes the pressure inside skyrocket. Those molecules are crammed together, less room to wiggle, so more direct thwacks against the container walls. So, shrinking the container's volume definitely forces up the pressure. Option B is a sure thing – it will increase pressure.

(Moving on, adding more stuff usually makes things more intense, doesn't it? Especially with gases.)

Now, C. Adding more gas molecules. When you cram more particles of gas into the same space (same volume, same temperature), you're just adding more things that can hit the container walls. Like throwing more dodgeballs into a small gym – you're bound to have more collisions. More collisions, all things being equal, means higher pressure. Think of adding more people to a room – more chance of bumping into the walls or someone else. Yep, Option C is off the list too. Adding more gas molecules, assuming the container volume and temperature stay the same, definitely leads to higher pressure.

(Okay, so we've ruled out A, B, and C. Only one option left, and it's got to be the mysterious one that doesn't fit the 'increase' pattern.)

Finally, D. Increasing the volume of the container. You see this coming, don't you? But just to nail it down (without using the forbidden word!), according to Boyle's Law again, pressure and volume are inversely proportional when temperature remains constant. So, if you expand the volume you have (say, you pull the pump handle on an exercise bike tire wider), you're giving those gas molecules, which are constantly zipping around with (let's say) average kinetic energy, more space to do their thing. They're moving at the same speed, but now the distances between collisions with the container walls are generally longer (sometimes much longer!). Slower rate of collisions (fewer impacts per second) on the wall means lower pressure for the gas.

Imagine you have two identical containers with the same amount and same temperature gas. One is squished, the other has a huge balloon attached, allowing the volume to expand. The pressure stays high because volume is small... and goes lower as volume increases. Yep, increasing the volume definitely means, other things being equal, the pressure will go down. That means Option D is the correct answer, the change that will NOT lead to increased pressure (in fact, it decreases pressure).

Think of it like spreading out for a bit, giving everyone more room – not as much crowding, not as much pressure to bump into anything critical immediately.

So, wrapping up: If you need to increase pressure, go for temperature (A), squeeze the volume (B), or just add some more gas (C). But if you're looking to keep the pressure stable or even lower it, increasing the container size is your direct route, according to Boyle's Law.

Got any gas-related curiosities swirling around in your mind? Do they ever pop up in unexpected ways? Let me know!

Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy