Question

A student observes the chemical process described by this equation:

4Al + 3O2 → 2Al2O3

How does the mass of the new substance compare to the total mass of the starting materials?

Answer 1

Answer:

Both are equal

Explanation:

Mass of starting material i.e Aluminium is $4.480 * 10^{-23}$ grams

The weight of oxygen is $2.65 * 10^{-23}$

There are 4 atoms of aluminium and 3 atoms of oxygen

Thus, the total mass of starting material is

$4 *$ mass of one atom of aluminium $+ 6 *$ mass of one atom of oxygen

$4 * 4.480 * 10^{-23} + 6* 2.65 * 10^{-23}$

$35.1 * 10^{-23}$ grams

Mass of new substance is also equal to

$4 *$ mass of one atom of aluminium $+ 6 *$ mass of one atom of oxygen

$4 * 4.480 * 10^{-23} + 6* 2.65 * 10^{-23}$

$35.1 * 10^{-23}$ grams