Question

\(X\), \(Y\) and \(Z\) are three allotropes of carbon. They are used in black ink, in water filters and as reducing agent in metallurgy respectively. The correct statement about their production is

• A. \(X\) is produced by heating wood at high temperatures in absence of air
• B. \(Y\) is produced by burning hydrocarbons in limited air
• C. \(Z\) is produced by heating coal at high temperatures in absence of air
• D. All three are produced by same chemical process

Hint:

Important forms of amorphous carbon: \[ \text{Carbon black (lamp black)} \rightarrow \text{Black inks, paints} \] \[ \text{Activated charcoal} \rightarrow \text{Water purification, adsorption} \] \[ \text{Coke} \rightarrow \text{Reducing agent in metallurgy} \] Coke is obtained by destructive distillation of coal.

Answer 1

The Correct Option is C

Step 1: Identify \(X\), \(Y\) and \(Z\).

• Used in black ink \(\rightarrow\) Carbon black (Lamp black)

• Used in water filters \(\rightarrow\) Activated charcoal

• Used as reducing agent in metallurgy \(\rightarrow\) Coke
Therefore, \[ X=\text{Carbon black} \] \[ Y=\text{Activated charcoal} \] \[ Z=\text{Coke} \]

Step 2: Check each statement.

Option (A) Heating wood in absence of air produces \[ \text{Wood charcoal}, \] not carbon black. Hence, \[ \boxed{\text{False}} \]

Option (B) Activated charcoal is not produced by burning hydrocarbons in limited air. Burning hydrocarbons in limited air produces carbon black (lamp black). \[ \boxed{\text{False}} \]

Option (C) Coke is obtained by destructive distillation of coal. That is, \[ \text{Heating coal at high temperature in absence of air}. \] \[ \boxed{\text{True}} \]

Option (D) The three allotropes are obtained by different processes. \[ \boxed{\text{False}} \]

Final Answer: \[ \boxed{\text{Z is produced by heating coal at high temperatures in absence of air}} \] \[ \boxed{\text{Answer = (C)}} \]