Menghitung Tetapan Kesetimbangan Berdasarkan Tekanan (Kp) | Kesetimbangan Kimia | Kelas 11

Summary

This educational video tutorial explains how to determine the equilibrium constant (Kp) for chemical reactions involving gases, focusing on calculating Kp based on partial pressure data. It covers step-by-step instructions, from writing balanced chemical equations to calculating partial pressures of gases and applying them in the Kp formula. The tutorial includes detailed examples, illustrating concepts with reactions like nitrogen, hydrogen, and ammonia, and carbon dioxide and carbon monoxide. With clear explanations and practical examples, viewers can confidently understand and apply the Kp calculation method in various equilibrium reactions.

Takeaways

• 😀 Kp (equilibrium constant based on pressure) is calculated using the partial pressures of the gases involved in a chemical reaction.
• 😀 The general formula for Kp is the product of partial pressures of the products raised to their stoichiometric coefficients, divided by the product of partial pressures of the reactants raised to their respective coefficients.
• 😀 To determine Kp, first write the balanced chemical equation, determine the number of moles of substances at equilibrium, and then find the partial pressures of each gas.
• 😀 The partial pressure of a gas is calculated by multiplying the mole fraction of the gas by the total pressure.
• 😀 In Kp calculations, gases are considered, and solids or liquids are excluded from the equation because they do not affect the equilibrium pressure.
• 😀 The steps for determining Kp are similar to those for determining Kc (equilibrium constant based on concentration), but Kp uses pressure data rather than concentration data.
• 😀 For the example given, the calculation of Kp involves determining the partial pressures of the gases (NH3, N2, H2) and applying the formula for Kp.
• 😀 In a reaction where a reactant and product are gases, partial pressures are used to determine Kp, considering the coefficients from the balanced chemical equation.
• 😀 In the given example, the equilibrium constant Kp for a reaction involving ammonia (NH3) decomposition was found to be 0.75.
• 😀 If given a chemical reaction with a known total pressure and the moles of reactants and products, Kp can be calculated by first determining partial pressures and then applying them to the equilibrium expression.

Q & A

What is the purpose of determining the equilibrium constant (KP) in chemistry?

The purpose of determining KP is to calculate the equilibrium constant for a reaction based on the partial pressures of the gases involved. It helps understand the position of equilibrium for gaseous reactions.

What data is needed to calculate KP?

To calculate KP, you need data on the partial pressures of the gases involved in the reaction. The pressures are typically measured at equilibrium.

How do you calculate the partial pressure of a gas in equilibrium?

The partial pressure of a gas is calculated by multiplying the number of moles of the gas by the total pressure and dividing it by the total number of moles of all gases in the system.

What is the general formula for KP?

The general formula for KP is the product of the partial pressures of the products raised to the power of their coefficients, divided by the product of the partial pressures of the reactants raised to the power of their coefficients.

What is the difference between KP and KC?

KP involves partial pressures of gases, while KC involves concentrations of gases or solutions. KP is used for reactions involving gases, and KC is used when the concentration of reactants and products is important.

How do you determine the equilibrium constant KP from a balanced reaction equation?

To determine KP from a balanced reaction equation, write the equilibrium expression based on the coefficients of the reactants and products. Then, substitute the partial pressures of the gases into the formula and solve.

In the example problem with N2, H2, and NH3, how was the partial pressure of NH3 calculated?

The partial pressure of NH3 was calculated by multiplying its mole fraction (1 mol/4 mol total) by the total pressure (10 atm), resulting in 2.5 atm.

In the second example, what is the process for finding KP when ammonia decomposes?

The process includes writing the balanced equation, determining the moles of substances at equilibrium, calculating the partial pressures of gases, and then substituting the values into the formula for KP.

How do you handle solids in KP calculations?

Solids are not included in the KP calculation because their activity is considered constant and does not affect the equilibrium constant.

What was the final value of KP for the ammonia decomposition reaction example?

The final value of KP for the ammonia decomposition reaction was 0.75, calculated based on the partial pressures of nitrogen, hydrogen, and ammonia.