CHEM. formulas.?

Question

if im supposed to have 4.5 moles of Oxygen what coefficient do i put in front of the O(2)???

NH(3) + O(2) ----> N(2) + H(2)O.

Answer 1

The balanced equation is:

4 NH3 + 3 O2 --> 2 N2 + 6 H2O

Balancing determines the coefficients. If you have 4.5 moles of O2, then you use the coefficients to determine:

4.5 moles * 4/3 = 6 moles of NH3 used
4.5 moles * 2/3 = 3 moles of N2 formed
4.5 moles * 6/3 = 9 moles of H2O formed

Answer 2

First balance the equation:

NH3 + O2 ---> N2 + H2O

becomes

4NH3 + 3O2 ---> 2N2 + 6H2O


The number of moles of oxygen do not impact the balancing of the equation, but the coefficients we just found will determined how much NH3 you need to react with 4.5 moles O2

4.5 [mol O2] * 4 [mol NH3] / 3 [mol O2] = 6 mole NH3