by classifying into categories that get smaller and smaller these are the classification steps : life , domain , kingdom , phylum , class, order , family , genus , and species every time you narrow it down the option gets smaller and smaller till there's none left except the species it self .
Here's link to the answer:
bit.
ly/3a8Nt8n
For every 2 Mol NaOH you would get 1 Mol N2H4
Multiple by 2 because it was give u right answer