Question

Fill in the blank with the correct number to balance the equation: 4Al + 3O2 → 2Al2O3. (Enter only a whole number.)

a) 6
b) 4
c) 5
d) 7

Answer 1

To balance the equation 4Al + 3O2 → 2Al2O3, you need to multiply the coefficients of Al and Al2O3 to obtain equal numbers of aluminum atoms on both sides. The correct number to balance the equation is 8 (option d).

Step-by-step explanation:

To balance the equation 4Al + 3O2 → 2Al2O3, we need to ensure that there are an equal number of each element on both sides of the equation. Here's how we can balance it:

1. On the left side, there are 4 aluminum atoms and 3 oxygen atoms. On the right side, there are 2 aluminum atoms and 3 oxygen atoms. To balance the aluminum, we can multiply the coefficient of Al2O3 by 2: 4Al + 3O2 → 4Al2O3
2. Now we have 8 aluminum atoms on the right side, so we need 8 aluminum atoms on the left side. We can achieve this by multiplying the coefficient of Al by 2: 8Al + 3O2 → 4Al2O3

The balanced equation is 8Al + 3O2 → 4Al2O3. Therefore, the correct number to balance the equation is 8 (option d).