Limestone, chalk and marble are different forms of ______.
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. Calcium carbonate
Limestone, marble, and chalk are different forms of the compound calcium carbonate (CaCO3).
- It is the disodium salt of carbonic acid with alkalinizing properties.
- When it is dissolved in water, sodium carbonate forms carbonic acid and sodium hydroxide.
- Sodium hydroxide, as a strong acid, neutralizes gastric acid, thereby acting as an antacid.
- It occurs extensively in rocks worldwide, and ground calcium carbonate results directly from the mining of limestone.