Question

How many miles of h2o are required to produce 4.5 miles of hno3 according the following 3no2+h2o 2hno3+no

Answer 1

sure looks like 4.5/2 = 2.25

and that's "moles"

Answer 2

oobleck. I thought you would do better than that; e.g., "depends on the number of miles in a mole" or "depends on the mass of one mile or the milomolar mass"