Question

in the combustion of methane $ch_4 + 2o_2
ightarrow co_2 + 2h_2o$, how many hydrogen atoms are present in the products?
a. 8
b. 6
c. 2
d. 4

Explanation:

Step1: Identify product with hydrogen

The products are $CO_2$ and $2H_2O$. Hydrogen is in $2H_2O$.

Step2: Calculate hydrogen atoms

In $H_2O$, there are 2 hydrogen atoms per molecule. Since there are 2 molecules of $H_2O$ (coefficient 2), the total number of hydrogen atoms is $2\times2 = 4$.

Answer:

d. 4