Answer:
Explanation:
The first two answers are the correct ones. Sometimes C can be true, but it is not a condition. Some equations produce many more products than reactants and some equations are made from more reactants than products.
The last one is normally not true, but the three equations I choose below do give D to be true. Still it does not happen all the time.
C8H18 + 12.5 O2 ===> 8CO2 + 9H20 This is the combustion equation that drives your engine. The coefficients do not add.
Same number of reactants as products.
CH4 + 2O2 ==> CO2 + 2H2O
More products than reactants.
Cu + 4HNO3 ==> Cu(NO3)2 + 2NO2 + 2H2O
More Reactants than products.
H2 + I2 ==> 2HI