Question

Classification of kerogen is based on the relative amount of Carbon (C), Hydrogen (H) and Oxygen (O). Which ONE of the following options is CORRECT about Type II kerogen?

• A. It is low in aliphatic compounds and H:C ratio < 0.84.
• B. It is rich in aliphatic compounds and H:C ratio < 0.84.
• C. It is low in aliphatic compounds and H:C ratio > 1.0.
• D. It is rich in aliphatic compounds and H:C ratio > 1.0.

Hint:

Remember: Type II kerogen is oil-prone, rich in aliphatic content, and has H:C ratio around or above 1.0.

Answer 1

The Correct Option is D

Step 1: Recall kerogen classification.
Kerogen is classified into three types based on elemental composition (H:C and O:C ratios): - Type I: Algal origin, very rich in hydrogen, H:C > 1.25. - Type II: Marine plankton origin, intermediate, H:C around 1.0-1.25. - Type III: Terrestrial plant origin, poor in hydrogen, H:C < 0.84. Step 2: Focus on Type II kerogen.
Type II kerogen is: - Rich in aliphatic compounds. - Has a hydrogen-to-carbon ratio \(\text{H:C} > 1.0\). - This makes it oil-prone. Step 3: Match with options.
From the given options: - (A) and (B) correspond to Type III kerogen. - (C) is incorrect since Type II is not low in aliphatics. - (D) matches the description. Final Answer: \[ \boxed{\text{(D) Rich in aliphatic compounds and H:C ratio > 1.0}} \]