Question

Bredig arc method cannot be used to prepare colloidal solutions of which of the following?
A) ${\text{Pt}}$
B) ${\text{Fe}}$
C) ${\text{Ag}}$
D) ${\text{Au}}$

Answer 1

In chemistry, periodic tables play a vital role. In the periodic table there are totally $118$ elements. In the periodic table there are totally $18$ columns and $7$ rows. The columns are called groups. Hence, $18$ groups in the periodic table. The rows are called periods. Hence, totally $7$ period in the table. The atomic number of iron is $26$ and the symbol is ${\text{Fe}}$. The mass number of the iron is $55.845$. Gold is one of the transition elements in the periodic table. The atomic number of gold is $79$ and the mass number of gold is $196.967$. The symbol of gold is ${\text{Au}}$.The symbol of silver is ${\text{Ag}}$. The atomic number of silver is $47$. The mass number of silver is $107.868g$. The symbol of platinum is ${\text{Au}}$.The symbol of silver is${\text{Pt}}$. The atomic number of platinum is $78$. The mass number of platinum is $195.08$.

Complete answer:
The preparation of colloidal solution of metals like gold, silver and platinum by using potassium hydroxide is known as Bredig arc method. In this method iron is not able to form colloidal solutions.
According to the above discussion, the Bredig arc method cannot be used to prepare colloidal solutions of iron.

Hence, option B is the correct answer.

Note:
We must have to remember that the atomic number of the atom depends on the number of protons or the number of electrons. The atomic number of the atom is equal to the number of protons or the number of the electrons. The mass number of the atom depends on the number of protons and the number of neutrons. The mass number of the atom is equal to the sum of the number of protons and the number of neutrons in the atom. Each element in the periodic table has a certain group and period.