Question

hgo + cl₂ → hgcl + o₂
c + h₂ → ch₄
challenge problem: give it your best shot!
c₂h₆ + o₂ → co₂ + h₂o

Explanation:

Step1: Balance carbon atoms

$$\text{C}_2\text{H}_6+\text{O}_2 ightarrow2\text{CO}_2+\text{H}_2\text{O}$$

Step2: Balance hydrogen atoms

$$\text{C}_2\text{H}_6+\text{O}_2 ightarrow2\text{CO}_2+3\text{H}_2\text{O}$$

Step3: Balance oxygen atoms

$$2\text{C}_2\text{H}_6 + 7\text{O}_2 ightarrow4\text{CO}_2+6\text{H}_2\text{O}$$

Answer:

$$2\text{C}_2\text{H}_6 + 7\text{O}_2 ightarrow4\text{CO}_2+6\text{H}_2\text{O}$$