Class X Science: Acids, Bases, Salts, and Chemical Reactions

Vocabulary flashcards generated from lecture notes covering the fundamentals of Acids, Bases, Salts, pH, indicators, as well as Chemical Reactions, Equations, Balancing, and Reaction Types.

Acids

Substances that donate protons ($H^+$ ions) during a chemical reaction, have a sour taste, and turn blue litmus paper red.

Bases

Substances that accept protons ($H^+$ ions) or donate hydroxide ions ($OH^-$) in a chemical reaction, have a bitter taste, feel slippery or soapy to the touch, and turn red litmus paper blue.

Indicators

Substances that change their color or smell in the presence of an acid or a base, helping to identify whether a solution is acidic, basic, or neutral.

Olfactory Indicators

Substances whose smell changes in acidic or basic solutions, allowing identification based on odor changes (e.g., onion extract, vanilla extract, clove oil).

Neutralisation Reaction

An acid-base reaction in which an acid combines with a base to form a corresponding salt and water, involving the combination of $H^+$ and $OH^-$ ions.

Alkalis

Bases that are soluble in water.

Hydronium Ion

The $H_3O^+$ ion formed when a hydrogen ion ($H^+$) combines with a water molecule in aqueous solution.

Strong Acid

An acid that completely ionizes in aqueous solution to release a high concentration of $H^+$ ions, such as hydrochloric acid ($HCl$) or sulphuric acid ($H_2SO_4$).

Weak Acid

An acid that partially ionizes in water to release a lower concentration of $H^+$ ions, such as acetic acid ($CH_3COOH$) or carbonic acid ($H_2CO_3$).

pH Scale

A scale ranging from $0$ to $14$ used to measure the strength of acids and bases by quantifying the concentration of $H^+$ ions in a solution.

Universal Indicator

A mixture of several indicators used to determine the pH of a solution by displaying different colors across values from $0$ to $14$.

Milk of Magnesia

Magnesium hydroxide ($Mg(OH)_2$), a mild basic substance used as an antacid to neutralize excess stomach acid.

Acid Rain

Rainwater with a pH below $5.6$, caused by atmospheric oxides like $SO_2$ and $NO_2$ reacting with water to form sulphuric acid ($H_2SO_4$) and nitric acid ($HNO_3$).

Salts

Ionic compounds composed of positively charged cations and negatively charged anions held together by ionic bonds, formed through the reaction between an acid and a base.

Chlor-Alkali Process

An industrial process involving the electrolysis of aqueous sodium chloride ($NaCl$) solution (brine) to produce sodium hydroxide ($NaOH$), chlorine gas ($Cl_2$) at the anode, and hydrogen gas ($H_2$) at the cathode.

Bleaching Powder

Calcium oxychloride ($CaOCl_2$), produced by reacting chlorine gas ($Cl_2$) obtained from the chlor-alkali process with dry slaked lime ($Ca(OH)_2$).

Baking Soda

Sodium hydrogen carbonate ($NaHCO_3$), a chemical compound prepared using sodium chloride, water, carbon dioxide, and ammonia, utilized in baking, antacids, and fire extinguishers.

Baking Powder

A mixture of baking soda ($NaHCO_3$) and a mild edible acid, such as tartaric acid, combined with cornstarch.

Washing Soda

Sodium carbonate decahydrate ($Na_2CO_3 \times 10H_2O$), obtained by recrystallization of sodium carbonate, used for softening hard water and in cleaning products.

Water of Crystallization

A fixed number of water molecules bound into the crystal structure of a salt, such as the five water molecules in copper sulphate ($CuSO_4 \times 5H_2O$).

Plaster of Paris

Calcium sulfate hemihydrate ($CaSO_4 \times \frac{1}{2}H_2O$), produced by heating gypsum ($CaSO_4 \times 2H_2O$) to $373\text{ K}$ ($100^\text{o}\text{C}$).

Dead Burnt Plaster

Completely anhydrous calcium sulfate formed when Plaster of Paris is heated above $200^\text{o}\text{C}$, losing all water of crystallization.

Physical Change

A change in shape, size, or physical state of a substance without altering its chemical composition.

Chemical Change

A process resulting in a composition change of a substance along with changes in shape, size, or state, creating new chemical identities.

Chemical Reaction

A process in which original substances undergo a transformation to yield new substances with different chemical properties.

Chemical Equation

A representation of a chemical reaction using symbols and chemical formulas to show reactants and products.

Reactants

Substances that undergo a chemical change during a chemical reaction.

Products

Substances formed as a result of a chemical change in a reaction.

Precipitate

An insoluble solid that forms and settles out of solution following a chemical reaction.

Exothermic Reaction

A chemical reaction that releases energy, typically in the form of heat, to its surroundings.

Endothermic Reaction

A chemical reaction in which heat energy is absorbed from the surroundings.

Catalyst

A substance that speeds up a chemical reaction or lowers the required temperature/pressure without being consumed in the process.

Combination Reaction

A chemical reaction in which two or more reactants combine to form a single product.

Decomposition Reaction

A chemical reaction in which a single reactant breaks down into two or more simpler elements or compounds when supplied with heat, electricity, or light.

Thermolytic Decomposition

A decomposition reaction brought about by thermal energy (heating).

Electrolytic Decomposition

A decomposition reaction driven by passing an electric current through a liquid or solution.

Photolytic Decomposition

A decomposition reaction initiated by exposure to light energy.

Displacement Reaction

A chemical reaction where a more reactive element displaces a less reactive element from its chemical compound.

Double-Displacement Reaction

A chemical reaction in which two ionic compounds exchange their cations and anions to form two new compounds.

Oxidation

A chemical process involving the addition of oxygen to a substance or the removal of hydrogen from it.

Reduction

A chemical process involving the addition of hydrogen to a substance or the removal of oxygen from it.

Redox Reaction

A chemical reaction in which oxidation and reduction take place simultaneously.

Oxidising Agent

A substance that causes oxidation in another substance by donating oxygen or removing hydrogen, becoming reduced in the process.

Reducing Agent

A substance that causes reduction in another substance by supplying hydrogen or removing oxygen, becoming oxidised in the process.

Corrosion

The gradual destruction or weakening of metal surfaces caused by chemical reactions with atmospheric oxygen, moisture, or acids.

Rusting

The oxidation process in which iron reacts with air and water to form hydrated ferric oxide, a reddish-brown flaky substance.

Tarnishing

The discoloration of silver metal when exposed to air due to reactions with hydrogen sulfide and oxygen, forming black silver sulfide ($Ag_2S$).

Rancidity

The spoilage of oil- or fat-containing foods caused by oxidation upon exposure to air, leading to an unpleasant smell and taste.