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Grade 11Physical Chemistry

the reversible reaction n2(g)+3h2(g) gives 2nh3 at 500 degrees the value of kp is 1.44 into 10 ^ 8 answer with explanation

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8 Years agoGrade 11
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ApprovedApproved Tutor Answer1 Year ago

In the context of chemical reactions, particularly reversible ones, the equilibrium constant (Kp) provides valuable insight into the relationship between the concentrations of reactants and products at equilibrium. For the reaction you mentioned, where nitrogen gas (N2) and hydrogen gas (H2) combine to form ammonia (NH3), the equilibrium constant Kp is given as 1.44 x 10^8 at 500 degrees Celsius. Let's break this down to understand what it means and how it relates to the reaction.

The Reaction and Its Components

The balanced chemical equation for the reaction is:

  • N2(g) + 3H2(g) ⇌ 2NH3(g)

This indicates that one mole of nitrogen reacts with three moles of hydrogen to produce two moles of ammonia. The reaction is reversible, meaning that ammonia can decompose back into nitrogen and hydrogen under certain conditions.

Understanding Kp

The equilibrium constant Kp is defined for gaseous reactions and is expressed in terms of the partial pressures of the gases involved. For the reaction above, Kp can be calculated using the formula:

  • Kp = (P_NH3)^2 / (P_N2 * (P_H2)^3)

Where P represents the partial pressures of the respective gases at equilibrium. The value of Kp tells us about the extent of the reaction at equilibrium:

  • If Kp > 1, the products are favored at equilibrium.
  • If Kp < 1, the reactants are favored.

Interpreting the Value of Kp

In your case, Kp = 1.44 x 10^8, which is significantly greater than 1. This indicates that at 500 degrees Celsius, the formation of ammonia is highly favored. In practical terms, this means that at equilibrium, there will be a much higher concentration of NH3 compared to N2 and H2.

Implications of a High Kp Value

A high Kp value suggests that the reaction proceeds almost to completion under the specified conditions. This can be particularly useful in industrial applications, such as the Haber process, which synthesizes ammonia for fertilizers. The high Kp indicates that under the right conditions (like high pressure and moderate temperature), ammonia can be produced efficiently.

Factors Affecting the Reaction

While Kp gives us a snapshot of the reaction at a specific temperature, several factors can influence the position of equilibrium:

  • Temperature: Increasing the temperature for an exothermic reaction (like the formation of ammonia) will shift the equilibrium to favor the reactants, potentially lowering Kp.
  • Pressure: Increasing pressure favors the side of the reaction with fewer moles of gas. In this case, moving from 4 moles of reactants (1 N2 + 3 H2) to 2 moles of product (2 NH3) favors the formation of ammonia.
  • Catalysts: While they do not affect Kp, catalysts can speed up the rate at which equilibrium is reached.

In summary, the reaction N2(g) + 3H2(g) ⇌ 2NH3(g) at 500 degrees Celsius with a Kp of 1.44 x 10^8 indicates a strong tendency to produce ammonia under those conditions. Understanding Kp helps chemists manipulate conditions to optimize product yield in various applications.