Equilibrium

Chemistry · Class 11

Simulation · Chemistry · Class 11

Heating limestone in a closed vessel

"Heating limestone in a closed vessel" is a free, interactive Class 11 Chemistry simulation for NEET and JEE, built on the NCERT section "Homogeneous and heterogeneous equilibria; Kp" in Equilibrium. CaCO3 heated in a closed vessel: the CO2 pressure settles to Kp whatever the amount of solid, and only temperature moves it; a side panel computes Kp/Kc = (RT)^Δn for chosen reactions. NEET has asked about this idea 2 times in 10 years of papers. JEE Main asked 52 questions from this chapter across the 42 shifts Lumi has analysed (2017–2026).

From the lesson Homogeneous and heterogeneous equilibria; Kp in Equilibrium. Change the values and watch what happens.

Heating limestone in a closed vesselChemistry · Class 11

What it shows

NCERT § "Homogeneous Equilibria"; § "Heterogeneous Equilibria"

CaCO3 heated in a closed vessel: the CO2 pressure settles to Kp whatever the amount of solid, and only temperature moves it; a side panel computes Kp/Kc = (RT)^Δn for chosen reactions.

Controls

3 to try

  • SliderCaCO3 mass 1–100 g
  • Slidertemperature 900–1200 K
  • Segmentedreaction for Kp-Kc: H2+I2 / PCl5 / N2+3H2 / CaCO3

Try this

Triple the mass of CaCO3 and show p(CO2) unchanged; then pick the reaction for which Kp = Kc.

Common mistake

Including pure solids in K; Δn as reactants minus products.

In NEET

10 years of papers

Asked 2 times in 10 years of NEET.

See the past questions: Chemical Equilibrium, Equilibrium (chapter)

In JEE Main

42 shifts analysed

52 questions from Equilibrium across the 42 JEE Main shifts Lumi has analysed (2017–2026).

See the past questions

The idea behind it

NCERT § "Homogeneous Equilibria"; § "Heterogeneous Equilibria"

  • In a homogeneous equilibrium all species are in the same phase, such as all gases or all in one solution.
  • For gases, partial pressures can replace concentrations, giving Kp; the two are linked by Kp = Kc(RT)^Δn.
  • Δn = (moles of gaseous products) − (moles of gaseous reactants) from the balanced equation.
  • When pressure is in bar and concentration in mol L⁻¹, R = 0.0831 bar L mol⁻¹ K⁻¹.
  • If Δn = 0 (e.g. H₂ + I₂ ⇌ 2HI), Kp = Kc; for PCl₅(g) ⇌ PCl₃(g) + Cl₂(g), Δn = +1 and Kp = Kc(RT).
  • In a heterogeneous equilibrium more than one phase is present, such as water in equilibrium with its vapour or CaCO₃(s) ⇌ CaO(s) + CO₂(g).
  • The concentrations of pure solids and pure liquids are constant and are left out of the K expression; for the decomposition of CaCO₃, Kp = p(CO₂).
  • Even though pure solids and liquids do not appear in K, they must be present for the heterogeneous equilibrium to exist.

Questions

5 answers

What does the "Heating limestone in a closed vessel" simulation show?
CaCO3 heated in a closed vessel: the CO2 pressure settles to Kp whatever the amount of solid, and only temperature moves it; a side panel computes Kp/Kc = (RT)^Δn for chosen reactions.
What mistake does the "Heating limestone in a closed vessel" simulation fix?
A common mistake it clears up: including pure solids in K; Δn as reactants minus products.
Has NEET asked about this idea?
Yes. NEET has asked about this idea 2 times in 10 years of papers.
Does JEE Main ask questions from Equilibrium?
Yes. JEE Main asked 52 questions from this chapter across the 42 shifts Lumi has analysed (2017–2026).
Is this simulation free?
Yes. It is free and runs in the browser on a phone or a laptop. It belongs to the lesson "Homogeneous and heterogeneous equilibria; Kp" in Equilibrium (Class 11 Chemistry).

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