What happens to water when it heats up
Water properties that depend on temperature
Water is the most widespread substance on the planet, with a special feature that distinguishes it from other liquids: when heated up to 40 degrees, water expands, and decreases if the heating temperature does not reach 40 degrees.
Unique properties of water
There is no other substance on earth that is as important to human beings as water. Oceans and seas occupy three quarters of the planet’s surface, and another 20% of the land surface is covered with snow and ice – water in a solid state. If it weren’t for water, which directly influences the climate, the Earth would turn into a lifeless chunk of rock flying through space.
The most unique quality of water is its immortality. In one day, humanity uses at least 1 billion tons of water, while the total amount of the resource on the planet remains the same. Millions of years ago, there was as much water on the earth’s surface as there is today. The living organisms that inhabit the planet learned to adapt to unfavorable conditions: cold, heat and darkness. No organism exists without water – this substance is contained in all animals and plants. Three quarters of the human body is made up of water.
Main properties of water:
• no smell or taste;
• capable of existing in three aggregate states;
• capable of moving from one aggregate state to another
An experiment showing the properties of water in heating and cooling
To carry out this experiment at home, we need two crystallizers and two laboratory flasks with a gas pipe, and also the following substances: ice, hot water and water of room temperature.
Pour the water of room temperature into two identical flasks, mark the water level and lower them in two containers – one with hot water and one with ice in it. What’s the result of the experiment? The water in the flask lowered into the hot water rises above the mark. The water in the flask placed in the ice sinks below the mark.
Conclusion: as a result of heating water expands, and after cooling water contracts.
An experiment demonstrating the properties of water when kept in different conditions
You should conduct this experiment at home in the evening. Fill three identical vessels with 100 ml of water – cups will be suitable. Place one cup on the window sill, the second on the table, and the third next to the heater. In the morning, compare the results: in the cup placed on the windowsill, the water evaporated by one third, in the glass on the table the water evaporated by half, and the cup by the heater is empty and dry – the water evaporated completely. Conclusion: water evaporation depends on the temperature of the environment, the higher it is the more swiftly water evaporates.
Experiment: turning steam into water
To conduct the experiment, prepare special equipment:
• a spirit burner;
• a metal plate;
• a flask with a gas pipe.
Pour water into the flask and heat it over the spirit burner until it boils. Hold the cold metal plate by the gas pipe – the steam will settle on the plate, turning into drops of water. The transformation of the gaseous water into liquid is called condensation. Conclusion: under intense heating, water turns into steam and returns to a liquid state on contact with a cold surface.
Heating water to a boiling state
Water that reaches boiling point has characteristic features: the liquid seethes, bubbles form inside it, and a thick steam rises up. This happens because water molecules receive additional energy from the source of warmth during heating, they vibrate and move more quickly.
During lengthy heating, the liquid reaches boiling point – bubbles of steam appear on the walls of the vessel. If the boiling doesn’t stop, the process continues until all of the water turns into gas. If the temperature is increased, pressure rises, the water molecules move more quickly and overcome the intermolecular forces that bind them. The atmospheric pressure resists the steam pressure, and the water boils when the steam pressure exceeds the outside pressure, or reaches it.