Mohon bantuannya untuk soal ini​

Berikut ini adalah pertanyaan dari Titin2312 pada mata pelajaran Kimia untuk jenjang Sekolah Menengah Atas

Mohon bantuannya untuk soal ini​
Mohon bantuannya untuk soal ini​

Jawaban dan Penjelasan

Berikut ini adalah pilihan jawaban terbaik dari pertanyaan diatas.

Jawaban:

Penjelasan:

Lain kali bilangin ke gurunya suruh siapin tabel nilai termodinamika (atau siapin sendiri terus upload gambar tabelnya)

a)

\Delta H^{\theta} (Mg_{(s)}) = 0 \;\dfrac{kJ}{\text{mol}}, \Delta H^{\theta} (Pb^{2+}_{(aq)}) = -1.7 \;\dfrac{kJ}{\text{mol}}, \Delta H^{\theta} (Mg^{2+}_{(aq)}) = -466.9\;\dfrac{kJ}{\text{mol}}, \\\\\Delta H^{\theta} (Pb_{(s)}) = 0\;\dfrac{kJ}{\text{mol}}\\

\Delta H^{\theta}_{total} = \sum( \Delta H^{\theta}_{produk} -\Delta H^{\theta}_{reaktan} ) \\\Delta H^{\theta}_{total} = \Delta H^{\theta} (Mg^{2+}_{(aq)}) + \Delta H^{\theta} (Pb_{(s)}) - (\Delta H^{\theta} (Mg_{(s)})+\Delta H^{\theta} (Pb^{2+}_{(aq)}))\\\Delta H^{\theta}_{total} = -466.9 + 1.7\\\Delta H^{\theta}_{total} = -465.2 \;\dfrac{kJ}{\text{mol}}\\

\Delta S^{\theta} (Mg_{(s)}) = 32.68 \;\dfrac{kJ}{\text{mol}}, \Delta S^{\theta} (Pb^{2+}_{(aq)}) = 10.5 \;\dfrac{kJ}{\text{mol}}, \Delta S^{\theta} (Mg^{2+}_{(aq)}) = -138.1\;\dfrac{kJ}{\text{mol}}, \\\\\Delta S^{\theta} (Pb_{(s)}) = 64.81\;\dfrac{kJ}{\text{mol}}\\

\Delta S^{\theta}_{total} = \sum( \Delta S^{\theta}_{produk} -\Delta S^{\theta}_{reaktan} ) \\ \\\Delta S^{\theta}_{total} = \Delta S^{\theta} (Mg^{2+}_{(aq)}) + \Delta S^{\theta} (Pb_{(s)}) - (\Delta S^{\theta} (Mg_{(s)})+\Delta S^{\theta} (Pb^{2+}_{(aq)}))\\\Delta S^{\theta}_{total} = -138.1 + 64.81 - (32.68+10.5) = -116.47 \;\dfrac{kJ}{\text{mol}}\\

\Delta G^{\theta}_{total} = \Delta H^{\theta}_{total} - (T_{celsius}+273)\cdot \Delta S^{\theta}_{total}\\\Delta G^{\theta}_{total} =-465.2 + 298\cdot 116.47\\ \boxed{\boxed{\Delta G^{\theta}_{total} = 34242.86\;\dfrac{kJ}{\text{mol}}}}

mencari nilai Kc :

\Delta G^{\theta}_{total} = -R(T_{celsius}+273)\cdot \ln(K_c) \to K_c = e^{^{\textstyle -\dfrac{\Delta G^{\theta}_{total} }{R\cdot (T_{celsius}+273)}}}\\\\\boxed{\boxed{K_c = e^{^{\textstyle -\dfrac{34242.86 }{0.008314\cdot 298}}} \approx 3.604\cdot 10^{-6081}}}

b)

\Delta H^{\theta} (Br_2_{(l)}) = 0 \;\dfrac{kJ}{\text{mol}}, \Delta H^{\theta} (I^{-}_{(aq)}) = -55.19\;\dfrac{kJ}{\text{mol}}, \Delta H^{\theta} (Br^{-}_{(aq)}) = -120.9\;\dfrac{kJ}{\text{mol}}, \\\\\Delta H^{\theta} (I_2_{(s)}) = 0\;\dfrac{kJ}{\text{mol}}\\

\Delta H^{\theta}_{total} = \sum( \Delta H^{\theta}_{produk} -\Delta H^{\theta}_{reaktan} ) \\ \Delta H^{\theta}_{total} = -(0-2\cdot 55.19- (-2\cdot 120.9 + 0))\\ \Delta H^{\theta}_{total} = -131.42 \;\dfrac{kJ}{\text{mol}}

\Delta S^{\theta} (Br_2_{(l)}) = 152.23 \;\dfrac{kJ}{\text{mol}}, \Delta S^{\theta} (I^{-}_{(aq)}) = 11.13\;\dfrac{kJ}{\text{mol}}, \Delta S^{\theta} (Br^{-}_{(aq)}) = 80.71\;\dfrac{kJ}{\text{mol}}, \\\\\Delta S^{\theta} (I_2_{(s)}) = 116.14\;\dfrac{kJ}{\text{mol}}\\

\Delta S^{\theta}_{total} = \sum( \Delta S^{\theta}_{produk} -\Delta S^{\theta}_{reaktan} ) \\\Delta S^{\theta}_{total} = 2\cdot 80.71 + 116.14 - (152.23 + 2\cdot 11.13) = 103.07 \;\dfrac{kJ}{\text{mol}}\\

\Delta G^{\theta}_{total} = \Delta H^{\theta}_{total} - (T_{celsius}+273)\cdot \Delta S^{\theta}_{total}\\\Delta G^{\theta}_{total} = -131.42 - 298\cdot 103.07 \\ \boxed{\boxed{\Delta G^{\theta}_{total} = -30846.28\;\dfrac{kJ}{\text{mol}}}}

mencari nilai Kc :

K_c = e^{^{\textstyle -\dfrac{\Delta G^{\theta}_{total} }{R\cdot (T_{celsius}+273)}}}\\\\\boxed{\boxed{K_c = e^{^{\textstyle \dfrac{30846.28 }{0.008314\cdot 298}}} \approx 1.136\cdot 10^{5407}}}

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Last Update: Fri, 23 Sep 22