Q&A for How to Make Water Gel

It depends on what substance you are talking about. Water vapour turns to a gas at 100 degrees Celsius and it turns to a liquid below that temperature level. Some substances do not turn into liquids at all whether you heat it or cool it a good example is iodine, this is called sublimation.

No, it will not change to liquid state. The only way to liquefy agar is to heat it up to about 95°C (about 203° Fahrenheit).

For the first method, no, it is not safe. For the second method, it is likely safe as it is just agar and water, unless you have skin sensitivity to agar.

Hand sanitizer most likely would not use agar. You would usually use aloe vera gel, as it can help counteract the drying induced by alcohol.

You generally cannot due to the amount of sugar and other ingredients in drinks like Sprite.

You can use cornstarch mixed with water to create a marbling bath. It's a readily available option, but the effects might not be as crisp as with water gel. Thickeners like methylcellulose and carrageenan can also be alternatives.

Yes. To use food coloring in agar gel, mix 20 ml of agar powder with 880 ml of boiling water. Once cooled to 60°C, add 100 ml of 0.1M NaOH and your food coloring, then allow it to cool further.

Yes, agar can be used to make a semi-liquid hydrogel. Agar forms a gel when dissolved in water and cooled. Agar gelation occurs during cooling, not heating, so you need to mix agar with a liquid, heat to dissolve, and let it cool to form a hydrogel without continuous cooking.