Hydrated compound

The video tutorial explains the concept of hydrated salts, focusing on copper sulfate, which contains water molecules within its crystal structure. When heated, the water is released, changing the salt's appearance from blue to white, a process that can be reversed by adding water. The video also highlights the giant gypsum crystals found in Mexico's Naika caves, which are composed of calcium, sulfur, and oxygen.

What is a key characteristic of hydrated salts like copper sulfate?

• They are always dry and powdery.

• They contain water molecules within their crystal structure.

• They are found only in caves.

• They cannot change color.

What happens to hydrated copper sulfate when it is heated?

• It melts into a liquid.

• It turns into a gas.

• It remains unchanged.

• It changes from blue crystals to a white powder.

How can the change in copper sulfate be reversed after heating?

• By exposing it to sunlight.

• By re-adding water.

• By adding more salt.

• By cooling it down.

Where are the giant gypsum crystals located?

• In the Sahara Desert.

• In the Arctic Circle.

• In Mexico's Naika caves.

• In the Amazon rainforest.

What elements make up the gypsum crystals found in Naika caves?

• Calcium, sulfur, and oxygen.

• Carbon, hydrogen, and nitrogen.

• Iron, magnesium, and silicon.

• Sodium, chlorine, and potassium.