Question

Consider the following Chemical equation: a Al₂O₃ + b HCl → c AlCl₃ + d H₂O
In order to balance this chemical equation, the values of a, b, c and d must be

• A. 1, 6, 2 and 3
• B. 1, 6, 3 and 2
• C. 2, 6, 2 and 3
• D. 2, 6, 3 and 2

Answer 1

The Correct Option is A

Step 1: Write the unbalanced chemical equation:
The unbalanced chemical equation is:
a Al₂O₃ + b HCl → c AlCl₃ + d H₂O

Step 2: Balance the aluminum atoms:
On the left side, there are 2 aluminum (Al) atoms in Al₂O₃, so we need 2 AlCl₃ on the right side to balance the aluminum atoms.
Thus, c = 2.

Step 3: Balance the chlorine atoms:
On the right side, we now have 2 AlCl₃, which gives 6 chlorine (Cl) atoms (2 × 3 = 6).
Therefore, we need 6 HCl molecules on the left side to balance the chlorine atoms.
Thus, b = 6.

Step 4: Balance the oxygen atoms:
On the left side, Al₂O₃ has 3 oxygen atoms.
On the right side, H₂O contains 1 oxygen atom per molecule. Since we have 3 oxygen atoms on the left, we need 3 H₂O molecules on the right to balance the oxygen atoms.
Thus, d = 3.

Step 5: Balance the hydrogen atoms:
On the left side, 6 HCl molecules give 6 hydrogen (H) atoms.
On the right side, 3 H₂O molecules give 6 hydrogen atoms (3 × 2 = 6).
So, the hydrogen atoms are already balanced.

Step 6: Conclusion:
The balanced equation is:
1 Al₂O₃ + 6 HCl → 2 AlCl₃ + 3 H₂O
Thus, the values of a, b, c, and d are:

1, 6, 2, and 3