Question

In the reaction N2H4 + 3O2 2NO2 + 2H2O , the mass of O2 required to combine with 745g of N2H4 will be

Answer 1

Answer:

assume the products are NO2 and H2O

N2H4 + 3O2 ==> 2NO2 + 2H2O

I will get you started but I'm having trouble understanding why you can't count bond broken and bonds formed.

For bonds broken, look at N2H4. There are four N-H bonds broken plus a N-N bond broken to make 5.

Look up the N-H bond to see how much energy is need to break that bond, multiply by 4 and add in the N-N bond. Then look up the O-O bond and multiply that by 3. Add that to the N2H2 bonds. That gives you the total energy needed to break the starting materials. Do the reverse for products.

delta H = reactants - products.

redox reaction.