Final answer:
The enthalpy change for the combustion reaction of dimethylhydrazine can be calculated using stoichiometry techniques. By multiplying the enthalpy change by the stoichiometric coefficient, you can determine the enthalpy change for different amounts of the substance involved. In this case, the enthalpy change for 1.5 moles of dimethylhydrazine is -2541 kJ.
Step-by-step explanation:
The combustion reaction of dimethylhydrazine is used to fuel rockets. The enthalpy change for the reaction can be calculated using stoichiometry techniques. By multiplying the enthalpy change by the stoichiometric coefficient of the reactant or product, you can determine the enthalpy change for different amounts of the substance involved. In this case, if the enthalpy change for a mole of dimethylhydrazine is -1694 kJ, the enthalpy change for 1.5 moles would be 1.5 * -1694 kJ = -2541 kJ.