The fizz

The idea

Vinegar (or lemon juice) mixed with baking soda fizzes and forms carbon dioxide gas, a chemical change: Vinegar + Baking soda → Carbon dioxide + Other substances.

Vinegar on baking soda

A pinch of baking soda waits in a tube. Now vinegar is poured on it. Listen and look.

What will you see?

• Nothing happens at all
• Fizzing, with gas bubbles
• It dissolves quietly, with no bubbles

Pour and watch

Pour each liquid down the funnel onto the baking soda. The gas goes through a tube into lime water. Remember: lime water turns milky for carbon dioxide.

A new gas forms

The gas turned lime water milky. So the gas is carbon dioxide.

When vinegar or lemon juice is mixed with baking soda, a fizzing, bubbling sound is heard and gas bubbles form. The gas is carbon dioxide. A new substance is formed, so this is a chemical change.

Vinegar + Baking soda → Carbon dioxide + Other substances

• Poured on baking soda | What you see | Lime water
• Vinegar | fizz, gas bubbles | turns milky
• Lemon juice | fizz, gas bubbles | turns milky
• Water | no fizz | stays clear

Notes

When vinegar or lemon juice is mixed with baking soda, it fizzes and forms carbon dioxide gas. This is a chemical change: Vinegar + Baking soda → Carbon dioxide + Other substances.

Check yourself

Vinegar is poured on baking soda and bubbles of gas come out. What kind of change is this?

Which mixture will NOT fizz?

The gas from the fizz is passed through lime water. What will happen?

Vinegar + Baking soda → Carbon dioxide + Other substances. Which is a new substance formed?

• A physical change, as only the look changes. A new gas is formed, so something more than the look has changed.
• A chemical change, as a new gas forms — correct. Yes! A new substance, carbon dioxide, is formed.
• No change, as the baking soda is still there. The fizz and the new gas show that a change has happened.
• Baking soda and water — correct. Yes! Water does not make carbon dioxide with baking soda.
• Baking soda and vinegar. This one fizzes and gives carbon dioxide.
• Baking soda and lemon juice. This one fizzes and gives carbon dioxide.
• The lime water stays clear. Clear lime water would mean the gas is not carbon dioxide.
• The lime water fizzes loudly. Lime water turns milky. It does not fizz.
• The lime water turns milky — correct. Yes! Carbon dioxide turns lime water milky.
• Carbon dioxide, on the right — correct. Yes! It is on the right of the arrow.
• Vinegar, the liquid on the left. Vinegar is on the left of the arrow. You start with it.
• Baking soda, the powder on the left. Baking soda is on the left of the arrow. You start with it.