# Chem

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Some very effective rocket fuels are composed of lightweight liquids. The fuel composed of dimethylhydrazine (CH3)2N2H2 mixed with dinitrogen tetroxide was used to power the Lunar Lander in its missions to the moon. The two components react according to the following equation:

(CH3)2N2H2 + 2 N2O4 -> 3 N2 + 4 H2O + 2 CO2

150 g of dimethylhydrazine reacts with the excess dinitrogen tetroxide and the product gases are collected at 27 degrees C in an evacuated 250 L tank.

a. What is the partial pressure of the nitrogen gas produced?

b. What is the total pressure in the tank, assuming that the reaction has a 90% yield?

I have no clue how to do this. Am I just to assume that the dimethyl is the limiting reagent because it says excess? I don't know what to do! Please help me out.

• Chem -

Yes, dimethylhydrazine is the limiting reagent. Just convert g dimethylhydrazine to moles, convert mole of that to moles N2, moles H2O, and moles CO2. Reduce each by 10% to take care of the 90% yield, then use PV = nRT to determine pressures of each. Add all of the partial pressures together to determine total pressure.

• Chem -

i googled this looking for a similar problem