In the 1980s, there was an international agreement to destroy all stockpiles of mustard gas, ClCH2CH2SCH2CH2Cl. When this substance contacts the moisture in eyes, nasal passages, and skin, the −OH groups of water replace the Cl atoms and create high local concentrations of hydrochloric acid, which cause severe blistering and tissue destruction. Complete and balance the equation for this reaction, and calculate ΔH°rxn. (See this table for bond energies. Use the lowest possible coefficients. Omit states-of-matter in your answer.)© BrainMass Inc. brainmass.com October 17, 2018, 12:13 am ad1c9bdddf
Reaction of mustard gas with water follows (balanced):
2 H2O (l) + ClCH2CH2SCH2CH2Cl (g) --> HOCH2CH2SCH2CH2OH (g) + 2 HCl (aq)
To calculate ΔH°rxn we must first determine how many bonds (and what type of bonds) are being broken and formed.
Types of bonds broken: Number of bonds broken: Bond enthalpy (kJ/mol) Energy change (kJ/mol)
The expert calculates ΔH°rxn from equations of reactions. The table for bond energies are provided.
Free Energy and Thermodynamics
1-Consider the reaction: I 2 (g)+Cl 2 (g)⇌2ICl(g). K p = 81.9 at 25 ∘ C.
Calculate ΔG rxn for the reaction at 25 ∘ C under each condition:
Part A: standard conditions.Express your answer using one decimal place.
Part B: at equilibrium
Part C: P ICl = 2.55atm ; P I 2 = 0.315atm ; P Cl 2 = 0.219atm .Express your answer using one decimal place.
2-Consider the following isomerization reactions of some simple sugars and values for their standard Gibbs free energy ΔG ∘:
reaction A: glucose-1-phosphate⟶ glucose-6-phosphate, ΔG ∘ =−7.28 kJ/mol
reaction B: fructose-6-phosphate ⟶, glucose-6-phosphate, ΔG =−1.67 kJ/mol
Calculate ΔG ∘ for the isomerization of glucose-1-phosphate to fructose-6-phosphate.
Express your answer with the appropriate units.
3-In photosynthesis, plants form glucose (C 6 H 12 O 6 ) and oxygen from carbon dioxide and water.
Part A :Write a balanced equation for photosynthesis.
Part B:Calculate ΔH ∘ rxn at 15 ∘ C .
Part C Calculate ΔS ∘ rxn at 15 ∘ C .
Part D:Calculate ΔG ∘ rxn at 15 ∘ C .
Part E :Is photosynthesis spontaneous?