Question

iala is conducting an experiment in her chemistry class. she needs to choose the balanced chemical equation for her project. which chemical equation should iala select as the balanced one? ch4+o2----co2+2h2o 4al+3o2----2al2o3 h2+o2----2h2o

Explanation:

Step1: Check the first equation

For \(CH_4 + O_2
ightarrow CO_2+2H_2O\), count the number of oxygen atoms. On the left - hand side, there are 2 oxygen atoms (from \(O_2\)), and on the right - hand side, there are \(2 + 2=4\) oxygen atoms (2 from \(CO_2\) and 2 from \(2H_2O\)). So it is unbalanced.

Step2: Check the second equation

For \(4Al + 3O_2
ightarrow 2Al_2O_3\), count the number of atoms.

• Aluminium (\(Al\)): On the left - hand side, there are 4 \(Al\) atoms. On the right - hand side, in \(2Al_2O_3\), \(2\times2 = 4\) \(Al\) atoms.
• Oxygen (\(O\)): On the left - hand side, there are \(3\times2=6\) oxygen atoms (from \(3O_2\)). On the right - hand side, in \(2Al_2O_3\), \(2\times3 = 6\) oxygen atoms.

Step3: Check the third equation

For \(H_2+O_2
ightarrow 2H_2O\), count the number of oxygen atoms. On the left - hand side, there are 2 oxygen atoms (from \(O_2\)), and on the right - hand side, there are 2 oxygen atoms (from \(2H_2O\)). But count the hydrogen atoms: On the left - hand side, there are 2 hydrogen atoms (from \(H_2\)), and on the right - hand side, there are \(2\times2 = 4\) hydrogen atoms. So it is unbalanced.

Answer:

\(4Al + 3O_2
ightarrow 2Al_2O_3\)