Ace the General Science chemistry syllabus by attempting our analytical chemistry question pool. Test your core concepts on the periodic table, chemical equations, chemical bonds, acids, bases, everyday chemistry compounds, metallurgy, and polymer mixtures backed by detailed answer insights.
Antoine Lavoisier discovered the role of oxygen in combustion, established the Law of Conservation of Mass, and wrote the first modern list of elements. [Memory Trick: He set the 'Laws' of chemistry, acting as a shiny 'Lavoisier' (advisor) of science.]
Heavy water contains the hydrogen isotope deuterium (which has a neutron in its nucleus). It slows down neutrons in nuclear reactors. [Memory Trick: 'D' stands for 'Double' heavy hydrogen isotope = D2O.]
Diamond possesses extreme hardness because of strong covalent bonds in its giant 3D crystal lattice. [Memory Trick: Carbon under immense pressure shines as a brilliant, unbreakable 'Diamond'.]
The gastric juices of the stomach contain hydrochloric acid (~0.5%), yielding a highly acidic pH level of 1.5 to 3.5. [Memory Trick: 'H'ighly 'C'orrosive 'L'iquid inside our belly = HCl.]
The pH scale goes from 0 (extremely acidic) through 7 (neutral water) up to 14 (extremely alkaline/basic). [Memory Trick: It ends at '14' (double of lucky number 7) which represents maximum alkaline strength.]
Carbon dioxide is denser than oxygen and acts as a heavy blanket over the fire, choking off the oxygen fueling the combustion. [Memory Trick: CO2 acts as a heavy 'C'hemically 'O'xygen '2' blocker.]
Nitrogen covers about 78% of dry atmosphere, while oxygen is second at ~21%, and argon third at ~0.93%. [Memory Trick: 'N'itrogen occupies the 'N'inety percent vicinity (almost 80%) of the atmosphere.]
Iron rust is a slow electrochemical oxidation process where iron reacts with water and oxygen to yield hydrated iron(III) oxide. [Memory Trick: Rust requires 'hydration' (water) + 'oxygen' (ferric oxidation) = Hydrated Ferric Oxide.]
Solder is traditionally a fusible alloy made of lead (Pb) and tin (Sn), possessing a low melting temperature. [Memory Trick: 'S'older joints are formed easily when a hot 'P'en ('P'b) melts a 'S'hinny 'n'ail ('S'n).]
Sulfur dioxide and nitrogen oxides react with water vapor in the atmosphere to formulate sulfuric and nitric acids, falling as acid rain. [Memory Trick: Industrial 'S'moke ('S'O2) and vehicle 'N'oise ('N'Ox) dissolve to melt structures with acid rain.]
Galvanizing covers iron or steel with a thin zinc layer, which acts as a sacrificial anode, corroding in place of the underlying metal. [Memory Trick: Galvan'z'ation wraps a shield of 'z'inc around the iron joint.]
Noble gases have a full outer shell of 8 valence electrons (stable octet, or duet for Helium), requiring zero donation/acceptance of electrons. [Memory Trick: Nobles are rich and 'completely satisfied' (full octet), so they don't interact with others.]
Plaster of Paris is calcium sulfate hemihydrate. When mixed with water, it rehydrates to form gypsum, setting into a hard solid. [Memory Trick: Plaster has only 'half' ('Hemi') a splash of water, while Gypsum has 'double' ('Di').]
Baking soda is sodium hydrogen carbonate (sodium bicarbonate). Under heat, it releases CO2 gas bubbles, expanding baked dough. [Memory Trick: When we cook at home, we buy ('Bi'-carbonate) baking soda to bake fluffy buns.]
Washing soda is sodium carbonate decahydrate, which cleans fabric by softening water and binding magnesium/calcium ions. [Memory Trick: No need to 'Bi' anything, just pure 'Sodium Carbonate' to wash clothes.]
Bleaching powder is calcium hypochlorite (calcium oxychloride). It releases active chlorine to sterilize organic stains and bacteria. [Memory Trick: 'Ca'lcium 'O'xy 'Cl2' (Chloride) = CaOCl2 which smells like chlorine pools.]
Liquefied Petroleum Gas (LPG) consists mainly of propane and butane gases under pressure, mixed with ethyl mercaptan for leak detection smells. [Memory Trick: Our kitchen 'PG' cylinders contain 'P'ropane and 'B'utane.]
Biogas is formed by anaerobic breakdown of organic waste, yielding roughly 50-75% methane (CH4) gas. [Memory Trick: Swamps and cows produce lots of 'Methane' (CH4) gas.]
Vinegar is basically a dilute solution of acetic acid (CH3COOH) generated through ethanol fermentation by acetic acid bacteria. [Memory Trick: 'A'cetate ('A'cetic) sounds like 'A'cidic vinegar salad dressing.]
Pencil lead contains no poisonous lead. It consists of a mixture of solid clay and soft graphite (a layered carbon allotrope that easily rubs off onto paper). [Memory Trick: Draw a 'graph' with 'Graphite' pencil leads.]
Mercury (Hg or quicksilver) has a very low freezing point (-39 Β°C), keeping it liquid at room temperature. It is widely used in traditional thermometers. [Memory Trick: 'Mercury' is the hot fluid planet inside clinical thermometer tubes.]
Bromine is the only nonmetallic chemical element that is a liquid at room temperature. It has a choking, pungent odor. [Memory Trick: 'Bro'mine is the red liquid 'Bro' of shiny gray metal Mercury.]
Wrought iron is highly pure iron containing slag fibers, making it malleable, rust-resistant, and easily welded. [Memory Trick: Iron that has been 'wrought' (worked/beaten) is cleaned of carbon residues, leaving it extremely pure.]
In 1828, Friedrich WΓΆhler successfully synthesized urea, proving carbon organic compounds could be produced synthetically from inorganic ammonium cyanate. [Memory Trick: 'Urea' is found in urine, proving human waste molecules could be made in a lab!]
Chlorofluorocarbons release chlorine atoms under UV light in the stratosphere, destructively cataloging ozone molecules. [Memory Trick: 'C'hlorine 'F'reezer 'C'hemicals = CFCs.]
Tap stars to rate this page: