Home › WAEC WASSCE › Chemistry › Stoichiometry of Chemical Reactions › After balancing ethane combustion with a fractio…
After balancing ethane combustion with a fractional O2 coefficient, how is the conventional integer equation obtained?
AMultiply every coefficient by 2
BMultiply every subscript by 2
CDivide every coefficient by 2
DDivide every subscript by 2
Answer & Solution
Correct answer: A. Multiply every coefficient by 2
1. The provisional equation is C2H6 + 7/2 O2 giving 3H2O + 2CO2.
2. Multiplying every coefficient by the same whole number keeps the atom balance intact.
3. Multiplying by 2 clears the halves and gives 2C2H6 + 7O2 giving 6H2O + 4CO2.
4. Subscripts must never be multiplied, since that would change the substances involved.
5. Dividing would make the fraction worse rather than clearing it.
_Source: OpenStax Chemistry (CC BY 4.0), Ch 4 "Stoichiometry of Chemical Reactions", section 4.1 Writing and Balancing Chemical Equations_
Related questions
In the reaction between sodium and chlorine, sodium is oxidised, which means chlorine:Ordering the three ways of writing a reaction from most to least detail about ions gives:When one element appears in more than one formula on the same side of an equation, you musWhen balancing a combustion equation, an odd number of oxygen atoms on the product side isCompounds that produce hydroxide ions by chemically reacting with water, rather than by diA double arrow is used in an acid equation to indicate that the acid is:A neutralisation reaction has an acid and a base as reactants and typically produces:Sodium hydroxide is classified as a strong base because in water it: