Question

which of the following equations represents a balanced chemical equation? remember: the number of atoms for each element should be equal on the reactant and product side. ch₄ + 2o₂ → co₂ + 2h₂o; h₂+o₂ → h₂o; caco₃ → cao + 2co₂; 2na + cl₂ → nacl

Explanation:

Step1: Analyze first equation

For $CH_4 + 2O_2
ightarrow CO_2+2H_2O$:

• Carbon: 1 atom on reactant side ($CH_4$) and 1 atom on product side ($CO_2$).
• Hydrogen: 4 atoms on reactant side ($CH_4$) and $2\times2 = 4$ atoms on product side ($2H_2O$).
• Oxygen: $2\times2= 4$ atoms on reactant side ($2O_2$) and $2 + 2\times1=4$ atoms on product side ($CO_2 + 2H_2O$). It is balanced.

Step2: Analyze second equation

For $H_2+O_2
ightarrow H_2O$:

• Oxygen: 2 atoms on reactant side ($O_2$) and 1 atom on product side ($H_2O$). It is not balanced.

Step3: Analyze third equation

For $CaCO_3
ightarrow CaO + 2CO_2$:

• Carbon: 1 atom on reactant side ($CaCO_3$) and 2 atoms on product side ($2CO_2$). It is not balanced.

Step4: Analyze fourth equation

For $2Na+Cl_2
ightarrow NaCl$:

• Sodium: 2 atoms on reactant side ($2Na$) and 1 atom on product side ($NaCl$). It is not balanced.

Answer:

$CH_4 + 2O_2
ightarrow CO_2+2H_2O$