Question

Nitric oxide, NO, is made from the oxidation of NH3, and the reaction is represented by the equation:4NH3 + 5O2 → 4NO + 6H2OWhat mass of O2 would be required to react completely with 7.42 g of NH3?

Answer 1

Answer: mass of Oxygen required = 17.45 g

Calculations:

• Molar mass NH3 ,= Molmass of N + ( 3xmol.mass of H ) = ,17 g/mol

,

• Molar mass of O2, = 2 x Mol.mass of O = 2*16 = ,32 g/mol

,

• Mass of NH3 = 7.42 g

The balanced equation of the chemical reaction:

$4NH_3+5O_2\Rightarrow4NO+6H_2O$

According to stoichemistry ,

• 4 moles of NH3 reacts with 5 moles of O2

,

• 4x17 g of NH3 reacts with 5x32 g of O2

• then , 7.42 g NH3 reacts with x mass of O2

Therefore mass of Oxygen will be :

$\begin{gathered} MassO_2\text{ = }\frac{7.42\cdot\text{ 5 }\cdot32}{4\cdot17} \\ \text{ = }17.45\text{ g } \end{gathered}$

This means that mass of Oxygen required = 17.45 g