More than 70% of the Earth's surface is covered by water.
Water is a poor heat and electricity conductor.
Water is colorless, odorless, and tasteless.
Capillary action, due to cohesive and adhesive forces, allows water to be drawn up from the roots to the leaves of plants.
Water is a basicneed of all life on Earth and no life can survive without it.
Water has a density of 1 g/cm^3.
Water has high surface tension, which allows insects like daddy longlegs to stay afloat on water.
The boiling point of water is 100°C, the freezing point is 0°C, and the melting point is 0°C.
Water is a compound made up of 2hydrogen and 1oxygen
Adhesive force is a force that attracts different molecules
Cohesive force is a force that attracts the same molecules.
Electrolysis is used to determine the composition of elements in a water molecule.
The ratio of the volume of gas produced is 1:2 (anode:oxygen gas, cathode:hydrogen gas).
The chemical symbol of water is H2O.
Electrolysis involves positive and negative electrodes (anode and cathode).
Dilute hydrochloric acid is added to distilled water because water is a poor electricity conductor.
During electrolysis, oxygen gas is produced at the anode and hydrogen gas is produced at the cathode.
Oxygen gas can be tested by using a glowing wooden splinter, which reignites.
Melting involves heat absorption. When heat is absorbed, the water particles will receive heat energy and move faster. Thus, convert the solid form to liquid.
Impurities in water such as Salt:
decreases the melting point
increases the boiling point
changes the taste
causes water to become denser
Hydrogen gas can be tested by using a glowing wooden splinter, which produces a “pop” sound
Water is a universal solvent, meaning it can dissolve a wide variety of substances.
Water is used as a solvent in the production of soft drinks.
Organic solvents, which are carbon-based, can be used to dissolve solutes that are insoluble in water.
Water is used as a solvent in domestic use and also as a rawmaterial in the manufacturing industry, agriculture, and medicine.
Water can be used for cooking, cleaning, bathing, and can dissolve different seasonings, detergents, and soaps.
Water is used in agriculture as fertilizers dissolve in water and are absorbed by the roots of plants.
Organic solvents are volatile and can be used in manufacturing aerosol substances such as spray paint, perfumes, and pesticides.
Water is known as a universal solvent as it can dissolve almost all substances, solids, liquids, or gases.
Examples of organicsolvents include alcohol, kerosene, acetone, turpentine, and ether.
Factors affecting the rate of solubility include the temperature of the solvent, rate of stirring, and size of the solute.
High temperature and rate of stirring cause particles to move rapidly, filling up the spaces between solvent and solute faster.
The higher the temperature of the solvent, the higher the rate of solubility.
The smaller the size of the solute, the higher the rate of solubility.
Solubility is the maximum amount of solute that can dissolve in 100 ml of solvent at a specific temperature.
The higher the rate of stirring, the higher the rate of solubility.
Smaller sized solutes means bigger total surface exposed to solvent particles.
Cold temperature caused solute particles and solvent particles to move slowly. Therefore, solute and solvent particles slowly fill up the spaces between them.
Water is a compound because it is produced when oxygen and hydrogen react chemically.
Boiling point of water increases as salt is added.