The enthalpy change, ΔH, for a reaction at constant pressure is defined as: ΔH = ΔE + PΔV. For which of the following reactions will ΔH be approximately equal to ΔE? Select all that apply. Group of answer choices 2 NO2(g) -> N2(g) + 2 O2(g)

Respuesta :

The given question is incomplete. The complete question is:

The enthalpy change, ΔH, for a reaction at constant pressure is defined as: ΔH = ΔE + PΔV. For which of the following reactions will ΔH be approximately equal to ΔE? Select all that apply. Group of answer choices

[tex]2NO_2(g)\rightarrow N_2(g)+2O_2(g)[/tex]

[tex]Ca(OH)_2(aq)+H_2SO_4(aq)\rightarrow 2H_2O(l)+caSO_4(s)[/tex]

[tex]C(s)+O_2(g)\rightarrow CO_2(g)[/tex]

None of the above

Answer:  

[tex]C(s)+O_2(g)\rightarrow CO_2(g)[/tex]

Explanation:

Relation of  with  is given by the formula:

[tex]\Delta H=\Delta E+{\Delta n_g}RT[/tex]     as

Where,

[tex]\Delta H[/tex] = enthalpy change

[tex]\Delta E[/tex]= internal energy change

R = Gas constant

T = temperature

[tex]\Delta n_g[/tex]= change in number of moles of gas particles = [tex]n_{products}-n_{reactants}[/tex]

1. For [tex]2NO_2(g)\rightarrow N_2(g)+2O_2(g)[/tex]

[tex]\Delta n_g=n_{products}-n_{reactants}=(3-2)=1[/tex]

2. For [tex]Ca(OH)_2(aq0+H_2SO_4(aq)\rightarrow 2H_2O(l)+CaSO_4(s)[/tex]

[tex]\Delta n_g=n_{products}-n_{reactants}=(0-0)=0[/tex]

3.  [tex]C(s)+O_2(g)\rightarrow CO_2(g)[/tex]

[tex]\Delta n_g=n_{products}-n_{reactants}=(0-0)=0[/tex]

Thus for reactions 2 and 3,  ΔH be approximately equal to ΔE

The options in which ΔH be approximately equal to ΔE are:

(ii) and (iii)

Enthalpy change:

The enthalpy change, ΔH, for a reaction at constant pressure is defined as:

[tex]\triangle H = \triangle E + \triangle n_g RT\\\\\triangle n_g=n_{\text{products}} -n_{\text{reactants}}[/tex]

Now, for each given choice we will calculate the change in number of moles of gas particles. Since, ΔH, for a reaction at constant pressure is defined as: ΔH = ΔE + PΔV

(i) [tex]2NO_2(g)---->N_2(g)+2O_2(g)[/tex]

[tex]\triangle n_g=n_{\text{products}} -n_{\text{reactants}}\\\\\triangle n_g=3-2=1[/tex]

(ii)[tex]Ca(OH)_2(aq)+H_2SO_4(aq)--->2H_2O(l)+CaSO_4(s)[/tex]

[tex]\triangle n_g=n_{\text{products}} -n_{\text{reactants}}\\\\\triangle n_g=0-0=0[/tex]

(iii) [tex]C(s)+O_2(g)---->CO_2(g)[/tex]

[tex]\triangle n_g=n_{\text{products}} -n_{\text{reactants}}\\\\\triangle n_g=0-0=0[/tex]

Thus for reactions (ii) and (iii) , ΔH be approximately equal to ΔE.

Therefore, correct options are (ii) and (iii).

Find more information about Enthalpy change here: brainly.com/question/14047927

The given question is incomplete. The complete question is:

The enthalpy change, ΔH, for a reaction at constant pressure is defined as: ΔH = ΔE + PΔV. For which of the following reactions will ΔH be approximately equal to ΔE? Select all that apply. Group of answer choices

(i) [tex]2NO_2(g)---->N_2(g)+2O_2(g)[/tex]

(ii) [tex]Ca(OH)_2(aq)+H_2SO_4(aq)--->2H_2O(l)+CaSO_4(s)[/tex]

(iii)  [tex]C(s)+O_2(g)---->CO_2(g)[/tex]

(iv) None of the above