Question

What number of molecules of O2 is consumed when 33.6 liters of STP H2O is produced according to the following reaction:

4NH3 (g) + 5O2 (g) ------> 4 NO(g) + 6 H20 (g)

Answer 1

To find the number of O2 molecules consumed to produce 33.6 L of H2O at STP, divide the volume of H2O by 22.414 L/mol to get the moles of H2O, then use the stoichiometric ratio from the balanced equation to find the moles of O2 required, and finally multiply by Avogadro's number to get the number of molecules.

Step-by-step explanation:

To determine the number of molecules of O2 consumed when 33.6 liters of STP H2O is produced, we can use the balanced chemical reaction and Avogadro's law. At STP, one mole of a gas occupies 22.414 liters. Therefore, we can calculate the number of moles of H2O produced by dividing 33.6 liters by 22.414 liters per mole:

Moles of H2O = 33.6 L / 22.414 L/mol = 1.5 mol

Looking at the balanced reaction:

4 NH3(g) + 5 O2(g) → 4 NO(g) + 6 H2O(g)

We can see that 5 moles of O2 are required to produce 6 moles of H2O. To find out how many moles of O2 are needed for the production of 1.5 moles of H2O, we set up a ratio:

Moles of O2 = (5 moles O2 / 6 moles H2O) x 1.5 moles H2O = 1.25 moles O2

To find the number of O2 molecules, we multiply the moles of O2 by Avogadro's number:

Number of O2 molecules = 1.25 moles x 6.022 x 1023 molecules/mole

The calculation will give us the number of Oxygen molecules consumed.