Phosphoric Acid and Phosphate Ions

The video tutorial explains how to derive the chemical formula for phosphoric acid (H3PO4). It begins by identifying that phosphoric acid does not start with 'hydro', thus eliminating certain possibilities. The tutorial then focuses on the 'ic' suffix, leading to the identification of the phosphate ion (PO4 3-). The process involves balancing the charges by adding three hydrogen ions (H+) to neutralize the negative charge of the phosphate ion, resulting in the formula H3PO4. The tutorial concludes with a confirmation of the derived formula.

What is the significance of the 'ic' suffix in phosphoric acid?

• It suggests the acid is binary.

• It indicates the presence of hydrogen.

• It means the acid is a strong acid.

• It helps identify the acid as an oxyacid.

What is the first step in deriving the formula for phosphoric acid?

• Finding the stem 'phosphor'.

• Locating the phosphate ion.

• Balancing the charges.

• Identifying the number of hydrogen atoms.

Why do we change 'ic' to 'ate' when writing the formula for phosphoric acid?

• To indicate the presence of oxygen.

• To find the corresponding ion in the table.

• To balance the chemical equation.

• To simplify the formula.

What is the charge of the phosphate ion found in the common ion table?

• Negative three

• Negative two

• Negative one

• Positive one

How many hydrogen atoms are needed to balance the charge of the phosphate ion?

• One

• Two

• Three

• Four

What is the net charge of phosphoric acid after balancing?

• Negative one

• Positive one

• Positive three

• Zero

What is the role of hydrogen in the formula for phosphoric acid?

• To act as a catalyst in the reaction.

• To increase the acidity of the solution.

• To stabilize the phosphate ion.

• To provide a positive charge to balance the phosphate ion.

What is the final chemical formula for phosphoric acid?

• H2PO4

• H3PO4

• HPO4

• H4PO4

Who is the narrator of the video?

• Dr. B

• Dr. D

• Dr. A

• Dr. C