How many molecules are there in 2.80 kg of hydrazine, #N_2H_2#? Chemistry The Mole Concept The Mole 1 Answer anor277 Feb 4, 2017 #"Hydrazine is"# #N_2H_4# Explanation: #"Moles of hydrazine"# #=# #"Mass of hydrazine"/"Molar mass of hydrazine"# #=(2.8xx10^3*g)/(32.05*g*mol^-1)~=87*mol.# And if there are #87*mol#, there are #87*molxxN_A#, where #N_A="the avocado number"=6.022xx10^23*mol^-1#, And #87*molxxN_A=5.26xx10^25# individual hydrazine molecules. #N_2H_2# is #"diazene"#, which can exist in two isomeric forms. Why? Answer link Related questions How do you calculate the number of moles from volume? How do you convert grams to mole? Question #258e5 Question #8d48c Why is the mole an important unit to chemists? What's the mole number? How does the mole relate to carbon 12? How does the mole relate to molecules and ions? How do you calculate the moles of a substance? How can I calculate the moles of a solute? See all questions in The Mole Impact of this question 5738 views around the world You can reuse this answer Creative Commons License