What are X and Y in the chemical equation Y NO2 + H2O -> X HNO3 + NO?

The coefficients X and Y can be found by balancing the given chemical equation.

Y NO2 + H2O -> X HNO3 + NO

In this equation, nitrogen dioxide (NO2) reacts with water (H2O) to form nitric acid (HNO3) and nitrous oxide (NO). A well balanced chemical equation is one in which the number of atoms of each species are same on both sides of the equation.

Let us calculate the number of atoms of each species on both sides of the equation:

Nitrogen (N): reactant : Y, product: X + 1

Oxygen (O) : reactant: 2Y + 1, product: 3X + 1

Hydrogen (H): reactant: 2, product: X

The balanced equation can be written as:

3 NO2 + H2O -> 2 HNO3 + NO

Thus, X = 2 and Y = 3.

One can check the number of atoms of each species on both sides of this equation to check that it is well balanced.