Change of state of gas and heat of vaporization
The point of this experiment is the heat of vaporization. This is the heat absorbed from the surroundings when a liquid turns into a gas. When water changes from a liquid to a gas, about 532 cal ( 44 kj / mol) is required per 1 g . Ethanol and acetone also absorb ambient heat.
Experiment 1: Not hot flame
you need : Acetone, water, 2 beakers, ethanol, tweezers, 1000 yen bill
Prepare water, acetone, and alcohol lamps from the left as shown in the photo. First, soak your hands in plenty of water, and then soak your fingertips in acetone. After that, if you light your hand, it will burn as shown in the picture. The miso of this experiment is not the burning acetone, but the water that was first put around the hands. Naturally, when things burn, they generate heat. At this time, water and acetone are also heated, and the state changes from liquid to gas. At that time, the heat of vaporization absorbs heat from the surroundings, so you can put up with it. When it gets hot, hold your hand, put out the fire and make a calm face. When you wave your hand, the flames will scatter. Never increase the amount!
Experiment 2: Non-burning paper and handkerchief
you need : 65-70% ethanol, handkerchief (no surrounding fibers), non-woven fabric, paper, gauze
Dilute ethanol to about 70%. If you put this on paper or cloth and burn it, the ethanol will burn out immediately, and the paper or cloth will remain as it is. (If fine fibers are sticking out, that part will be burnt. Non-woven fabric is easy to use. When using cloth, it is better to fold it around and sew it.) Money paper is also solid, so you can do it, but lessons So what's the problem?
The ethanol flame is transparent and difficult to see, so dissolve the salt so that it becomes an orange flame.
Experiment 3: Non-burning paper Part 2
ryou need : If there is no strong Japanese paper (no fibers coming out from the surroundings), is it a paper plate or a paper cup?
Even if you put water in a paper plate and heat it, it will not burn. You can do it with a paper cup, but the paper cup may have holes due to the extra protrusions. Of course, you can also fold the paper yourself. It is a paper pot. This is because even if water boils, it will only reach 100 ° C, so paper in contact with water will not reach 100 ° C or higher and will not ignite. Even balloons are okay for a while as long as there is water inside. If the box is folded, it will burn from the extra protrusions and water will leak more. The paper used in the paper pot is Japanese paper, which is fine and durable.
Experiment 4: Hot water that is not hot
Pour hot water of about 70 degrees into the spray bottle. The container is very hot. About 30 cm apart, spray hot water on your hands. It's surprisingly cold.
