When solid calcium carbonate (CaCO3) decomposes upon strong heating, it …

Chemistry Questions

When solid calcium carbonate (CaCO3) decomposes upon strong heating, it produces solid calcium oxide (CaO) and carbon dioxide gas (CO2) as described by the equation CaCO3(s) ‚aa CaO(s) + CO2(g). A 2.0 mol sample of CaCO3 is placed in a rigid 100 L reaction vessel that has been evacuated of air. The vessel is then heated to 898¬∞C, where the pressure of CO2 is constant at 1.00 atm and some CaCO3 remains. (a) How many moles of CO2 are present in the vessel at equilibrium?

Short Answer

The reaction involves the decomposition of calcium carbonate into calcium oxide and carbon dioxide, with 1.04 moles of CO‚CC at equilibrium. The temperature is converted from 898¬∞C to 1171 K for use in the ideal gas law, validating that the system maintains 1.00 atm pressure and the calculated gas conditions.

Step-by-Step Solution

Step 1: Understanding the Chemical Reaction

The reaction involves the decomposition of calcium carbonate (CaCO‚ÄöCE) into calcium oxide (CaO) and carbon dioxide (CO‚ÄöCC) when heated. The balanced equation for this reaction is:

  • CaCO‚ÄöCE(s) ‚Äöaa CaO(s) + CO‚ÄöCC(g)

At equilibrium, the system has a specific amount of carbon dioxide present, which is crucial for understanding the reaction dynamics. Here, we know that 1.04 moles of CO‚ÄöCC are present during equilibrium.

Step 2: Calculating the Temperature in Kelvin

To perform calculations involving gases, it is essential to convert the temperature from degrees Celsius to Kelvin. The conversion formula is:

  • K = ¬¨‚àûC + 273.15

In this case, the given temperature is 898°C, which converts to:

  • K = 898 + 273.15 = 1171 K

This temperature is used in the ideal gas law for further calculations.

Step 3: Utilizing the Ideal Gas Law

The ideal gas law is used to relate the pressure, volume, temperature, and number of moles of a gas. The formula is:

  • P ‚àöo V = n ‚àöo R ‚àöo T

In this scenario, we can plug in the values:

  • P = 1.00 atm
  • V = 100 L
  • R = 0.081 (L¬¨‚àëatm)/(K¬¨‚àëmol)
  • T = 1171 K

After calculating with the ideal gas equation, we confirm that the system indeed has 1.04 moles of CO‚ÄöCC, maintaining a constant pressure of 1.00 atm at equilibrium.

Related Concepts

Chemical Reaction

A process in which substances (reactants) transform into different substances (products) through breaking and forming chemical bonds

Equilibrium

A state in a chemical reaction where the concentrations of reactants and products remain constant over time, indicating that the forward and reverse reactions occur at the same rate

Ideal Gas Law

A physical law that describes the behavior of ideal gases in relation to pressure, volume, temperature, and the number of moles, expressed mathematically as pv = nrt.

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