Question

Balance this equation. If a coefficient of "1" is required, choose "blank" for that box. C2H6 + O2 → CO2 + H2O

Answer 1

Step 1: Write the unbalanced equation,

                                 C₂H₆  +  O₂    →    CO₂  +  H₂O

There are 2 C at left hand side and 1 carbon at right hand side. So, multiply CO₂ by 2 to balance C atoms at both side. So,

                                 C₂H₆  +  O₂    →   2 CO₂  +  H₂O

Now, count number of H atoms at both sides. There are 6 H atoms at left hand side and 2 at right hand side. Multiply H₂O by 3 to balance H atoms.


                                 C₂H₆  +  O₂    →   2 CO₂  +  3 H₂O

At last, balance O atoms. There are 2 O atoms at left hand side and 3 O atoms at right hand side. Multiply O₂ with 1.5 (i.e. 3/2) to balance O atoms. i.e.

                                 C₂H₆  +  3/2 O₂    →   2 CO₂  +  3 H₂O

Hence, the equation is balanced. If you want to make equation fraction free then multiply all equation with 2. i.e.

                           ( C₂H₆  +  3/2 O₂    →   2 CO₂  +  3 H₂O ) × 2

                                2 C₂H₆  +  3 O₂    →   4 CO₂  +  6 H₂O

Answer 2

Explanation:

In a balanced equation, number of atoms on both reactant and product side are equal.

For example, $C_{2}H_{6} + O_{2} \rightarrow CO_{2} + H_{2}O$

Number of atoms present on reactant side are as follows.

C = 2

H = 6

O = 2

Number of atoms present on product side are as follows.

C = 1

H = 2

O = 3

Therefore, to balance this equation multiply $C_{2}H_{6}$ by 2 and multiply $O_{2}$ by 7 on reactant side. Whereas multiply $CO_{2}$ by 4 and multiply $H_{2}O$ by 6 on product side.

Therefore, the balanced chemical equation is as follows.

          $2C_{2}H_{6} + 7O_{2} \rightarrow 4CO_{2} + 6H_{2}O$