Question

1. when the equation

_al(s) + _o₂(g) → _al₂o₃(s)
is correctly balanced using the smallest whole numbers, what will be the coefficient of al(s)?

Explanation:

Step1: Balance oxygen atoms

The number of oxygen atoms in \(O_2\) is \(2\) and in \(Al_2O_3\) is \(3\). The least - common multiple of \(2\) and \(3\) is \(6\). So, we set the coefficient of \(O_2\) as \(3\) (\(3\times2 = 6\) oxygen atoms) and the coefficient of \(Al_2O_3\) as \(2\) (\(2\times3=6\) oxygen atoms).

Step2: Balance aluminum atoms

After balancing oxygen, for aluminum atoms, since we have \(2\) molecules of \(Al_2O_3\) (each \(Al_2O_3\) has \(2\) aluminum atoms), the total number of aluminum atoms on the product side is \(2\times2 = 4\). So, the coefficient of \(Al\) on the reactant side is \(4\).

The balanced equation is \(4Al(s)+3O_2(g)\to2Al_2O_3(s)\)

Answer:

\(4\) (the fourth option)