What Did We Test in This Experiment?
We are trying to see if concentration of one substance speeds up the reaction process. We can observe this by seeing how many drops of each acid it takes for the cabbage water (with dishwashing liquid) to reach its original colour.
What Did You Observe?
It should have taken fewer drops of the vinegar and lemon juice compared to the milk to turn the cabbage water (with dishwashing liquid) back to its original colour.
Why Does This Happen?
The colour change happens because red cabbages have a special chemical which allows us to see how acidic or basic a substance is. If something is more acidic, it means that it has a higher concentration of a certain type of particle.
Dishwashing liquid is a base. When acids react with bases in equal concentration, they become neutral. The cabbage water alone is neutral. When the dishwashing liquid is added, it becomes more basic. Lemon juice, milk and vinegar are all acids with different levels of concentration (different scores on the pH scale).
It took fewer drops of vinegar and lemon juice to turn the cabbage water to its original colour because vinegar and lemon juice have a much higher concentration than milk.
This experiment has showed why higher concentration speeds up the reaction rate.
Dishwashing liquid is a base. When acids react with bases in equal concentration, they become neutral. The cabbage water alone is neutral. When the dishwashing liquid is added, it becomes more basic. Lemon juice, milk and vinegar are all acids with different levels of concentration (different scores on the pH scale).
It took fewer drops of vinegar and lemon juice to turn the cabbage water to its original colour because vinegar and lemon juice have a much higher concentration than milk.
This experiment has showed why higher concentration speeds up the reaction rate.