Answer:
31.5 grams
Explanation:
I'm guessing you meant how many grams are in 1.75 moles of H2O
You need a periodic table for this first you're going to find the atomic mass for Hydrogen (1.008) and oxygen (15.999)
since there are 2 Hydrogen in the problem you'll multiply 1.008 by 2 giving you 2.016
You'll then add your 1 Nitrogen to this to get 18.015: this number is the grams for 1 mole of H2O, you'll then multiply 18.015 by 1.75 to find the grams for that many moles (31.52625) this is how many grams are in 1.75 moles of H2O
Don't forget sig figs though so your answer will be 31.5