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.)
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.