Posted by Alex on .
I am not sure if I have the right answer or not to the following question. One mole of NO2 would be produced from how many moles of molecular nitrogen> According the equation N2 + 202 > 2NO2. I was thinking maybe 2. Does anyone know if I am right or wrong. Thanks

Chemistry 
DrBob222,
N2 + 2O2 ==> 2NO2
No.
You can think of this several ways.
1. The equation tells us 2 moles NO2 are given by 1 mole N2. We must divide 2moles NO2 by 2 to obtain 1; therefore, we must divide 1 mole N2 by 2 to obtain 1/2 mole. 1/2 mole N2 is the answer.
2. Use dimensional analysis using the coefficients in the balanced equation.
1 mole NO2 is what you want; therefore,
1 mole NO2 x (1 mole N2/2 moles NO2) = 1 mole x 1/2 = 1/2 mole N2. Note how moles NO2 in the numerator cancel with moles NO2 in the denominator leaving ONLY moles N2 for the units which is what you want.
3. Use ratio and proportion.
(1 mole N2/2 moles NO2) = (x moles N2/1 mole NO2)
Solve for x = 1/2 mole N2.