Chemistry : General Chemistry
Decantation, distillation, precipitation, boiling of water, freezing of water, and dissolving of salt in water are physical changes.
Rusting of iron (oxidation) is a chemical change.
The 'fizz' in soft drinks is caused by Carbon dioxide.
The combination of any substance with oxygen is known as oxidation.
HCl (Hydrochloric acid), H2SO4 (Sulfuric acid), and HNO3 (Nitirc acid) are famous acids.
Lemon juice is acidic in nature.
Acids turn blue litmus paper red.
NaOH (Sodium hydroxide) is a famous base.
The reaction of an acid with a base to produce only salt and water is called a neutralization reaction.
Solubility of a substance in a solvent usually increases with an increase in temperature.
If no more solute can be dissolved in a solvent at a given temperature then that solution is called a saturated solution.
Heat is liberated in exothermic reactions.
A substance that speeds up the rate of a chemical reaction without undergoing any physical or chemical change itself is known as a catalyst.
Chlorine gas is green in color.
Hydrogen gas is evolved when dilute Sulfuric acid is added to zinc.
A pH scale reading less than 7 indicates acidity.
A substance that absorbs moisture is called hygroscopic.
Charcoal, diamond, and graphite are allotropes of carbon. The lead of a pencil mainly contains graphite.
The two allotropes of phosphorus are Red and Yellow.
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