Metal Carbonates and Their Reactions With Acids
Metal Carbonates and Their Reactions With Acids
1. What Are Metal Carbonates?
A metal carbonate is a compound made from:
a metal element, and
a carbonate group, which contains carbon and oxygen together.
A metal carbonate is usually a solid and often appears as a white or colored powder.
Examples of metal carbonates (written in words only):
calcium carbonate – found in chalk, limestone, and marble
sodium carbonate – also called washing soda
magnesium carbonate
copper carbonate – usually green in color
2. What Happens When a Metal Carbonate Reacts With an Acid?
When any metal carbonate comes into contact with an acid, a very predictable reaction occurs. The products are always:
✔ a salt
✔ water
✔ carbon dioxide gas
This reaction produces bubbles or fizzing, which is the escaping carbon dioxide gas.
3. Word-Based Reaction Pattern
metal carbonate + acid → salt + water + carbon dioxide
This always happens, no matter what metal carbonate or what acid is used.
4. Examples (Word-Only)
A. Calcium carbonate reacting with hydrochloric acid
Products formed:
calcium chloride (a salt)
water
carbon dioxide gas
B. Magnesium carbonate reacting with sulfuric acid
Products formed:
magnesium sulfate (a salt)
water
carbon dioxide gas
C. Copper carbonate reacting with nitric acid
Products formed:
copper nitrate (a salt)
water
carbon dioxide gas
5. How To Test for Carbon Dioxide
You can confirm the gas using limewater:
When carbon dioxide is bubbled through limewater, the liquid becomes cloudy or milky.
This is because a white solid is formed in the mixture.
This change is the classic test for carbon dioxide.
6. Why Do Metal Carbonates React With Acids?
Metal carbonates contain the carbonate group, which reacts strongly with acids.Acids supply hydrogen ions, and carbonates break down when they meet these ions.
The carbonate group decomposes into:
carbon dioxide gas
water
The metal part of the carbonate and the leftover part of the acid combine to form a salt.
7. Uses and Applications
1. Antacid tablets
Magnesium carbonate is used to calm excess stomach acid through neutralization.
2. Building and erosion
Acid rain slowly dissolves calcium carbonate in rocks and buildings made from limestone or marble.
3. Identifying unknown substances
A fizzing reaction with acid is used in labs to confirm whether a substance is a metal carbonate.
4. Environmental chemistry
Carbon dioxide release and carbonate interactions play roles in ocean chemistry and geology.