How many moles of dinitrogen pentoxide are needed to produce 1.25 moles of nitric acid?

To determine the number of moles of dinitrogen pentoxide (N2O5) needed to produce 1.25 moles of nitric acid (HNO3), we need to consider the balanced chemical equation for the reaction between dinitrogen pentoxide and water.

The balanced equation is:

N2O5 + H2O → 2HNO3

From the equation, we can see that for every 1 mole of N2O5, it produces 2 moles of HNO3. Therefore, the molar ratio between N2O5 and HNO3 is 1:2.

To calculate the amount of moles of N2O5, we can use the following formula:

moles of N2O5 = moles of HNO3 x (1 mol N2O5 / 2 mol HNO3)

Substituting the given value:

moles of N2O5 = 1.25 mol HNO3 x (1 mol N2O5 / 2 mol HNO3)

moles of N2O5 = 0.625 mol N2O5

Thus, 0.625 moles of dinitrogen pentoxide are needed to produce 1.25 moles of nitric acid.