4NH3+5O2--->4NO+6H2O

determine the amount of oxygen needed to produce 1.2x10^4mol of nitrogen monoxide gas

5 moles

To determine the amount of oxygen needed to produce 1.2x10^4 moles of nitrogen monoxide (NO) gas, we need to analyze the balanced chemical equation:

4NH3 + 5O2 ---> 4NO + 6H2O

From the equation, we can see that the molar ratio between O2 and NO is 5:4. This means that for every 5 moles of O2, we can produce 4 moles of NO.

Now, we can set up a proportion to find the amount of O2 needed:

5 moles O2 / 4 moles NO = x moles O2 / 1.2x10^4 moles NO

Cross-multiplying, we get:

5 moles O2 * 1.2x10^4 moles NO = 4 moles NO * x moles O2

Rearranging the equation, we can solve for x:

x = (5 moles O2 * 1.2x10^4 moles NO) / 4 moles NO

x = 6x10^4 moles O2 / 4

x = 15x10^3 moles O2

Therefore, the amount of oxygen needed to produce 1.2x10^4 moles of nitrogen monoxide gas is 15x10^3 moles O2.