Why’s it hard for ketchup to flow?
Ketchup is not like water or an orange juice or any oil. It’s not completely liquid not completely solid. It is a kind of mixture as the bottle of ketchup we have to shake well before use. Why so? The solid particles in ketchup have a very special property; the particles of the tomato pulp stick together strongly. So when the bottle of tomato ketchup is left unused for like only minutes, it becomes so thick which resist motion. To beat its resistance, we have to shake the bottle well. When we shake the bottle, then its molecules loosen and the ketchup start to flow like cream.
Trying to pour tomato ketchup on your sandwich is not as easy like water or oil. You have to shake the bottle very well, whereas water or oil comes out smoothly. What is the reason behind this? Let’s try to find out the answer.
We already know that water is a liquid substance. But tomato ketchup is not a liquid; it is actually neither liquid nor solid. It depend on the factors like force, temperature or time. The solid particles in tomato ketchup have a special property that these particles of the tomato pulp stick together and become thick. So when tomato ketchup in the bottle is left untouched for some time, it becomes so thick that it gets a physical strength which resist motion. To overcome this resistance you will notice that you have to shake the ketchup bottle well. When you shake the ketchup bottle, then its molecules loosen and start to flow.