Skip to main content
Ch.15 - Chemical Equilibrium
Brown - Chemistry: The Central Science 14th Edition
Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232당신이 사용하는 게 아니라요?교과서 변경
모든 교과서Brown 14th EditionCh.15 - Chemical Equilibrium문제 81
15장, 문제 81

Solid NH4SH is introduced into an evacuated flask at 24 _x001F_C. The following reaction takes place: NH4SH(s) ⇌ NH3(g) + H2S(g). At equilibrium, the total pressure (for NH3 and H2S taken together) is 0.614 atm. What is Kp for this equilibrium at 24 _x001F_C?

검증된 단계별 안내
1
Identify the equilibrium reaction: NH4SH(s) ⇌ NH3(g) + H2S(g). Note that NH4SH is a solid and does not appear in the expression for Kp.
Write the expression for the equilibrium constant Kp for the reaction: Kp = P(NH3) * P(H2S), where P(NH3) and P(H2S) are the partial pressures of NH3 and H2S, respectively.
Recognize that at equilibrium, the total pressure is the sum of the partial pressures of NH3 and H2S: P(total) = P(NH3) + P(H2S) = 0.614 atm.
Assume that the partial pressures of NH3 and H2S are equal at equilibrium due to the stoichiometry of the reaction (1:1 ratio). Therefore, let P(NH3) = P(H2S) = x atm.
Set up the equation for total pressure: x + x = 0.614 atm, solve for x to find the partial pressures, and then substitute back into the Kp expression to find Kp.

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Equilibrium Constant (Kp)

The equilibrium constant (Kp) is a numerical value that expresses the ratio of the partial pressures of the products to the reactants at equilibrium for a given reaction. For the reaction NH4SH(s) ⇌ NH3(g) + H2S(g), Kp is calculated using the formula Kp = (P_NH3 * P_H2S) / P_NH4SH, where P represents the partial pressures of the gases involved. Since NH4SH is a solid, its activity is considered to be 1, simplifying the expression.
추천 영상:
가이드 코스
03:20
Equilibrium Constant Expressions

Partial Pressure

Partial pressure is the pressure exerted by a single component of a gas mixture. In this case, the total pressure of the gases NH3 and H2S at equilibrium is given as 0.614 atm. To find Kp, one must determine the individual partial pressures of NH3 and H2S, which can be derived from the total pressure and the stoichiometry of the reaction, assuming equal molar amounts of NH3 and H2S are produced.
추천 영상:
가이드 코스
00:48
Partial Pressure Calculation

Le Chatelier's Principle

Le Chatelier's Principle states that if a dynamic equilibrium is disturbed by changing the conditions, the system will adjust to counteract the change and restore a new equilibrium. In the context of the reaction NH4SH(s) ⇌ NH3(g) + H2S(g), if the pressure or temperature changes, the equilibrium position will shift to favor the formation of either reactants or products, affecting the values of Kp and the concentrations of the gases involved.
추천 영상:
가이드 코스
07:32
Le Chatelier's Principle
관련 실천
교과서 질문

A 0.831-g sample of SO3 is placed in a 1.00-L container and heated to 1100 K. The SO3 decomposes to SO2 and O2: 2SO3(𝑔) ⇌ 2 SO2(𝑔) + O2(𝑔) At equilibrium, the total pressure in the container is 1.300 atm. Find the values of 𝐾𝑝 and 𝐾𝑐 for this reaction at 1100 K.

1351
views
교과서 질문

Nitric oxide (NO) reacts readily with chlorine gas as follows: 2 NO(𝑔) + Cl2(𝑔) ⇌ 2 NOCl(𝑔) At 700 K, the equilibrium constant Kp for this reaction is 0.26. Predict the behavior of each of the following mixtures at this temperature and indicate whether or not the mixtures are at equilibrium. If not, state whether the mixture will need to produce more products or reactants to reach equilibrium.

(a) PNO = 0.15 atm, PCl2 = 0.31 atm, PNOCl = 0.11 atm

(b) PNO = 0.12 atm, PCl2 = 0.10 atm, PNOCl = 0.050 atm

(c) PNO = 0.15 atm, PCl2 = 0.20 atm, PNOCl = 5.10 × 10-3 atm

835
views
교과서 질문

As shown in Table 15.2, the equilibrium constant for the reaction N2(g) + 3 H2(g) ⇌ 2 NH3(g) is Kp = 4.34 × 10-3 at 300°C. Pure NH3 is placed in a 1.00-L flask and allowed to reach equilibrium at this temperature. There are 1.05 g NH3 in the equilibrium mixture. (b) What was the initial mass of ammonia placed in the vessel?

1061
views
교과서 질문

At 900 °C, 𝐾𝑐 = 0.0108 for the reaction

CaCO3(𝑠) ⇌ CaO(𝑠) + CO2(𝑔)

A mixture of CaCO3, CaO, and CO2 is placed in a 10.0-L vessel at 900°C. For the following mixtures, will the amount of CaCO3 increase, decrease, or remain the same as the system approaches equilibrium?

(a) 15.0 g CaCO3, 15.0 g CaO, and 4.25 g CO2

(b) 2.50 g CaCO3, 25.0 g CaO, and 5.66 g CO2

(c) 30.5 g CaCO3, 25.5 g CaO, and 6.48 g CO2

724
views
1
rank
교과서 질문

For the equilibrium PH3BCl3(𝑠) ⇌ PH3(𝑔) + BCl3(𝑔) 𝐾𝑝 = 0.052 at 60 °C. (b) After 3.00 g of solid PH3BCl3 is added to a closed 1.500-L vessel at 60 °C, the vessel is charged with 0.0500 g of BCl3(𝑔). What is the equilibrium concentration of PH3?

1220
views