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Select whether there is no work done by the system, work done by the system or work done by the surroundings for each system described below: A. H2O (l) \longrightarrow⟶ H2O (g) ΔH = 44.0 kJ/mol B. 2 NO (g) + O2 (g) \longrightarrow⟶ 2 NO2(g) ΔH = -114.1 kJ/mol C. Cl (g) + O3 (g) \longrightarrow⟶ ClO(g) + O2(g) ΔH = -163 kJ/mol D. CaCO3 (s) \longrightarrow⟶ CaO (s) + CO2(g) ΔH = 110.1 kJ/mol E. 4 NH3(g) + 5 O2(g) \longrightarrow⟶ 4 NO (g) + 6 H2O(l) ΔH = -906 kJ/mol

Respuesta :

IthaloAbreu

Answer:

A) work done by the system;

B) work is negligible;

C) work is negligible;

D) work done by the system;

E) work doe by the surroundigs.

Explanation:

The work is the energy that a gas gain or loses to expand or compress, respectivately. So, if the gas molecules increase, the work is done by the system, if they decrease, the work is done by the surroundigs, if they don't change, or if there is no gas in the reaction, the work is  negligible.

dsdrajlin

Regarding the work in the following reactions:

  • H₂O (l) ⟶ H₂O (g) ΔH = 44.0 kJ/mol                                                     There is work done by the system.
  • 2 NO (g) + O₂ (g) ⟶ 2 NO₂(g) ΔH = -114.1 kJ/mol                                   There is work done by the surroundings.
  • Cl (g) + O₃ (g) ⟶ ClO(g) + O₂(g) ΔH = -163 kJ/mol                                 There is no work done.
  • CaCO₃ (s) ⟶ CaO (s) + CO₂(g) ΔH = 110.1 kJ/mol                                 There is work done by the system.
  • 4 NH₃(g) + 5 O₂(g) ⟶ 4 NO (g) + 6 H₂O(l) ΔH = -906 kJ/mol               There is work done by the surroundings.

We can determine the work done (W) by the system or by the surroundings using the following expression.

[tex]W = -RT\Delta n(g)[/tex]

where,

  • R: ideal gas constant
  • T: absolute temperature
  • Δn(g): moles of gaseous products - moles of gaseous reactants

Since R and T are always positive, we can conclude that:

  • If Δn(g) > 0, W < 0, there is work done by the system.
  • If Δn(g) < 0, W > 0, there is work done by the surroundings.
  • If Δn(g) = 0, W = 0, there is no work done.

Let's select whether there is no work done by the system, work done by the system or work done by the surroundings for each system described below.

A. H₂O (l) ⟶ H₂O (g) ΔH = 44.0 kJ/mol

Δn(g) = 1 - 0 = 1. W < 0, there is work done by the system.

B. 2 NO (g) + O₂ (g) ⟶ 2 NO₂(g) ΔH = -114.1 kJ/mol

Δn(g) = 2 - 3 = -1. W > 0, there is work done by the surroundings.

C. Cl (g) + O₃ (g) ⟶ ClO(g) + O₂(g) ΔH = -163 kJ/mol

Δn(g) = 2 - 2 = 0. W = 0, there is no work done.

D. CaCO₃ (s) ⟶ CaO (s) + CO₂(g) ΔH = 110.1 kJ/mol

Δn(g) = 1 - 0 = 1. W < 0, there is work done by the system.

E. 4 NH₃(g) + 5 O₂(g) ⟶ 4 NO (g) + 6 H₂O(l) ΔH = -906 kJ/mol

Δn(g) = 4 - 9 = -5. W > 0, there is work done by the surroundings.

Regarding the work in the following reactions:

  • H₂O (l) ⟶ H₂O (g) ΔH = 44.0 kJ/mol                                                     There is work done by the system.
  • 2 NO (g) + O₂ (g) ⟶ 2 NO₂(g) ΔH = -114.1 kJ/mol                                   There is work done by the surroundings.
  • Cl (g) + O₃ (g) ⟶ ClO(g) + O₂(g) ΔH = -163 kJ/mol                                 There is no work done.
  • CaCO₃ (s) ⟶ CaO (s) + CO₂(g) ΔH = 110.1 kJ/mol                                 There is work done by the system.
  • 4 NH₃(g) + 5 O₂(g) ⟶ 4 NO (g) + 6 H₂O(l) ΔH = -906 kJ/mol               There is work done by the surroundings.

Learn more: https://brainly.com/question/14581707

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