Urea (CH4N2O) is a common fertilizer that is synthesized by the reaction of ammonia (NH3) with carbon dioxide. NH3 + CO2 = CH4N2O + H2O. In an industrial synthesis of urea, a chemist combines an excess of ammonia with 11.4 grams of carbon dioxide. Balance the reaction.
Doesn't really matter how much CO2 was used. The equation is unchanged.
NH3 + CO2 = CH4N2O + H2O
Balance the N: LS has 1, RS has 2, so
2NH3 + CO2 = CH4N2O + H2O
Now the H: LS has 6, RS has 6, so ok there
How about the C? LS has 1, RS has 1, so ok there
Finally, the O: 2 on LS and RS.
So we're done