JEE · Chemistry · States of Matter: Gases doubts
12 doubts found
Why does a sealed bag of chips puff up in the sun or on a mountain flight?
Two gas laws are at work.
Why do aerosol and deodorant cans warn 'do not heat or incinerate'?
At fixed volume, a gas's pressure rises in direct proportion to its absolute temperature (Gay-Lussac's law, P ∝ T).
Why do scuba divers get 'the bends' if they surface too quickly?
Gas solubility rises with pressure (Henry's law).
Why do real gases stop obeying PV = nRT at very high pressure or very low temperature?
The ideal-gas law assumes molecules take up no space and don't attract each other.
Open a perfume bottle in one corner and the whole room smells it — why, and what's fastest?
Gas molecules are in constant rapid random motion, so they diffuse and spread until evenly mixed, even against still air.
What does “Kinetic molecular theory” actually mean in States of Matter: Gases, and why does it matter for JEE?
gases are tiny, fast, far-apart particles in constant random motion; pressure comes from their collisions with the walls.
I keep getting “Kinetic molecular theory” questions wrong in States of Matter: Gases. What's the trap?
picturing gas molecules as touching or slow.
What does “Real vs ideal gas behaviour” actually mean in States of Matter: Gases, and why does it matter for JEE?
real gases deviate from PV = nRT at high pressure and low temperature, when molecular size and attractions can't be ignored.
I keep getting “Real vs ideal gas behaviour” questions wrong in States of Matter: Gases. What's the trap?
assuming every gas obeys the ideal equation under all conditions.
What is the difference between Boyle's law and Charles's law?
Boyle's law: at constant temperature, pressure and volume are inversely related (PV = constant); Charles's law: at constant pressure, volume is directly proportional to absolute temperature (V/T = constant).
What is the difference between diffusion and effusion?
Diffusion is gases spreading and mixing through one another; effusion is a gas escaping through a tiny hole — both are faster for lighter molecules (Graham's law).
When do I use PV = nRT in States of Matter: Gases, and what does it mean?
ideal gas equation of state.