Two unbalanced equations are shown.
i NH3 + O2 mc025-1.jpg NO + H2O
ii SeCl6 + O2 mc025-2.jpg SeO2 + Cl2
What can most likely be predicted after balancing both equations?
Four molecules of NH3 react with five molecules of O2 to produce four molecules of NO and six molecules of H2O.
One molecule of NH3 reacts with one molecule of O2 to produce one molecule of NO and two molecules of H2O.
One molecule of SeCl6 reacts with one molecule of O2 to produce one molecule of SeO2 and two molecules of Cl2.
Two molecules of SeCl6 react with one molecule of O2 to produce two molecules of SeO2

Question

Two unbalanced equations are shown.
i  NH3 + O2 mc025-1.jpg NO + H2O   
ii   SeCl6 + O2 mc025-2.jpg SeO2 + Cl2
What can most likely be predicted after balancing both equations?
Four molecules of NH3 react with five molecules of O2 to produce four molecules of NO and six molecules of H2O.
One molecule of NH3 reacts with one molecule of O2 to produce one molecule of NO and two molecules of H2O.
One molecule of SeCl6 reacts with one molecule of O2 to produce one molecule of SeO2 and two molecules of Cl2.
Two molecules of SeCl6 react with one molecule of O2 to produce two molecules of SeO2

abmon98 · Answer

Write down your given equation. 
NH3+O2-->NO+H2O
Write down the number of atoms that you have on each side of the equation
Reactant Side:N:1 H:3 O:2
Product Side: N:1 H:2 O:2
NH3+O2-->NO+3/2H2O
we get rid of the fraction by multiplying by 2
2NH3+2O2-->2NO+3H2O
Reactant side: N:2 H:6 O:4
Product side: N:2 H:6 O:5
Changes the Coefficient from 2 to 5/2 in O2
2NH3 + 5/2O2-->2NO+3H2O
Again we get rid of fraction by multiplying by 2
4NH3+5O2-->4NO+6H2O