Acid, Base and Salt

Vocabulary flashcards covering the properties, indicators, reactions, and common chemical products of acids, bases, and salts based on the lecture notes.

Acids

Substances that have a sour taste, change blue litmus paper to red, and produce hydrogen ions ($H^+$) or hydronium ions ($H_3O^+$) in the presence of water.

Bases

Substances that are bitter in taste, soapy to touch, and change red litmus paper to blue; they produce hydroxide ions ($OH^-$) in aqueous solutions.

Litmus solution

A purple dye extracted from lichen, a plant belonging to the division Thallophyta, used as a common acid-base indicator.

Acid-base indicators

Natural or synthetic materials, such as red cabbage leaves, turmeric, Hydrangea, Petunia, and Geranium, that indicate the presence of an acid or base in a solution.

Olfactory Indicators

Substances like onion, cloves, and vanilla whose odour changes depending on whether they are in an acidic or basic medium.

Neutralisation Reaction

A chemical reaction between an acid and a base to form salt and water, represented by the equation: Acid + Base $\rightarrow$ Salt + Water.

Basic nature of Metallic Oxides

The property shown by metal oxides because they react with acids to form salt and water, similar to the reaction of a base.

Acidic nature of Non-metallic Oxides

The property shown by non-metal oxides, such as carbon dioxide ($CO_2$), because they react with bases to form salt and water.

Antacids

Basic substances used to neutralize excess acidity in the stomach, such as milk of magnesia and sodium hydrogen carbonate ($NaHCO_3$).

Acid Rain

Rainwater that has a pH level less than $5.6$.

Methanoic acid

The acidic liquid injected into the skin by an ant sting or nettle leaves, causing burning pain.

Tooth Enamel

The hardest substance in the body, made of calcium phosphate, which begins to corrode when the mouth pH falls below $5.5$.

Chlor-alkali process

The process of passing electricity through brine (aqueous $NaCl$) to produce sodium hydroxide ($NaOH$), chlorine mapping at the anode, and hydrogen at the cathode.

Bleaching powder

Calcium oxychloride ($Ca(ClO)_2$), formed by the action of chlorine on dry slaked lime ($Ca(OH)_2$), used for bleaching textiles and disinfecting water.

Baking soda

Sodium bicarbonate ($NaHCO_3$), prepared using sodium chloride, water, ammonia, and carbon dioxide; it is used in cooking and as an antacid.

Washing soda

Sodium carbonate decahydrate ($Na_2CO_3 \times 10H_2O$), used in glass, soap, and paper manufacture, and for removing permanent hardness of water.

Water of crystallization

The fixed number of water molecules chemically attached to each formula unit of a salt in its crystal form.

Plaster of Paris

Calcium sulphate hemihydrate ($CaSO_4 \times \frac{1}{2}H_2O$), which becomes a hard solid mass of gypsum when mixed with water.

Gypsum

The hard solid mass ($CaSO_4 \times 2H_2O$) formed when Plaster of Paris reacts with water.