Question

part a
the reaction here shows a simple chemical reaction involving the combustion of ethane (c₂h₆), a fuel, in the presence of oxygen gas to form water and carbon dioxide (co₂). which coefficients can be placed in the blanks to correctly balance the equation?
a 1,3,2,3
b 2,7,4,6
c 2,6,4,7
d 2,4,3,2
part b
the reaction here shows a simple chemical reaction involving the combustion of ethane (c₂h₆), a fuel, in the presence of oxygen gas to form water and carbon dioxide (co₂). what is the primary source of hydrogen atoms in the water molecule on the product side?
a hydrogen from the atmosphere reacts with water to form oxygen
b carbon atoms recombine with oxygen to form hydrogen atoms.
c hydrogen atoms in ethane (c₂h₆) form new bonds with oxygen to form water.
d oxygen atoms from the reactant lose protons and electrons to form hydrogen.

Explanation:

Step1: Write the un - balanced equation

The combustion of ethane ($C_2H_6$) in oxygen ($O_2$) to form water ($H_2O$) and carbon - dioxide ($CO_2$) is: $C_2H_6+O_2
ightarrow H_2O + CO_2$.

Step2: Balance carbon atoms

There are 2 carbon atoms in $C_2H_6$. So, we put a coefficient of 2 in front of $CO_2$: $C_2H_6+O_2
ightarrow H_2O + 2CO_2$.

Step3: Balance hydrogen atoms

There are 6 hydrogen atoms in $C_2H_6$. So, we put a coefficient of 3 in front of $H_2O$: $C_2H_6+O_2
ightarrow3H_2O + 2CO_2$.

Step4: Balance oxygen atoms

On the right - hand side, there are 3 oxygen atoms in $3H_2O$ and 4 oxygen atoms in $2CO_2$, for a total of 7 oxygen atoms. So, we put a coefficient of $\frac{7}{2}$ in front of $O_2$: $C_2H_6+\frac{7}{2}O_2
ightarrow3H_2O + 2CO_2$. To get rid of the fraction, we multiply the entire equation by 2, giving $2C_2H_6 + 7O_2
ightarrow6H_2O+4CO_2$. So the coefficients are 2, 7, 4, 6.

Step5: Answer Part B

In a chemical reaction, atoms are conserved. In the combustion of ethane ($C_2H_6$), the hydrogen atoms in the water molecule on the product side come from the hydrogen atoms in ethane. The hydrogen atoms in ethane form new bonds with oxygen to form water.

Answer:

Part A: B. 2, 7, 4, 6
Part B: C. Hydrogen atoms in ethane ($C_2H_6$) form new bonds with oxygen to form water.