Some Basic Concepts of Chemistry Flashcards

Comprehensive vocabulary flashcards covering basic chemistry concepts, historical developments in India, measurement systems (SI units), laws of chemical combination, and concentration terms.

Chemistry

The branch of science that studies the preparation, properties, structure and reactions of material substances.

Philosopher’s stone (Paras)

A legendary substance sought by early chemists believed to be capable of converting baser metals like iron and copper into gold.

Elixir of life

A mythical substance sought in early chemical traditions that was believed to grant immortality.

Rasayan Shastra

The name for chemistry in ancient India, also referred to as Rastantra, Ras Kriya, or Rasvidya.

Faience

A sort of glass used in ornaments by the Harappans, created by melting and forging materials.

Nagarjuna

A great Indian scientist, chemist, alchemist, and metallurgist whose work Rasratnakar deals with the formulation of mercury compounds and metal extraction.

Chakrapani

The Indian scientist credited with discovering mercury sulphide and inventing soap using mustard oil and alkalies.

Acharya Kanda

The first proponent of the atomic theory (born in 600 BCE), who formulated the theory of indivisible particles called Paramãnu.

Paramãnu

According to Acharya Kanda, these are small indivisible particles that are eternal, indestructible, spherical, and in motion in their original state.

Nanotechnology

Termed in the context of ancient Ayurveda as the extreme reduction of particle size of metals, specifically the use of 'bhasma' in medicinal treatments.

Cisplatin and Taxol

Life-saving drugs provided by chemistry that are effective in cancer therapy.

AZT (Azidothymidine)

A chemical drug used for helping AIDS patients.

Matter

Anything which has mass and occupies space.

Solid

A state of matter where particles are held very close to each other in an orderly fashion with little freedom of movement, resulting in definite volume and shape.

Liquid

A state of matter where particles are close together but can move around, resulting in a definite volume but no definite shape.

Gas

A state of matter where particles are far apart and move easily and fast, resulting in no definite volume and no definite shape.

Pure Substance

A substance in which all constituent particles are the same in chemical nature, such as gold, silver, or water.

Homogeneous Mixture

A mixture where the components completely mix with each other and the composition is uniform throughout.

Heterogeneous Mixture

A mixture where the composition is not uniform throughout and different components are sometimes visible, such as salt and sugar mixed together.

Element

A substance whose particles consist of only one type of atoms, existing either as individual atoms or as molecules.

Compound

A substance obtained when two or more atoms of different elements combine together in a definite ratio, which can only be separated by chemical methods.

Physical Properties

Unique characteristics like colour, odour, melting point, and boiling point that can be measured or observed without changing the identity of the substance.

Chemical Properties

Characteristics like composition, combustibility, and reactivity with acids or bases that require a chemical change to be measured or observed.

Metre ($m$)

The SI unit of length defined by the fixed numerical value of the speed of light in vacuum $c$ to be $299792458$ when expressed in the unit $ms^{-1}$.

Kilogram ($kg$)

The SI unit of mass defined by taking the fixed numerical value of the Planck constant $h$ to be $6.62607015 \times 10^{-34}$ when expressed in the unit $Js$.

Mole ($mol$)

The SI unit of amount of substance containing exactly $6.02214076 \times 10^{23}$ elementary entities.

Mass

The amount of matter present in a substance, which remains constant regardless of location.

Weight

The force exerted by gravity on an object, which may vary from one place to another.

Density

The amount of mass per unit volume ($\text{Density} = \frac{\text{Mass}}{\text{Volume}}$), typically expressed in $kg/m^3$ or $g/cm^3$.

Temperature Conversion Formula ($^{\circ}C$ to $^{\circ}F$)

$$^{\circ}F = \frac{9}{5}(^{\circ}C) + 32$$

Temperature Conversion Formula ($^{\circ}C$ to $K$)

$$K = ^{\circ}C + 273.15$$

Scientific Notation

An exponential notation where any number is represented in the form $N \times 10^n$, where $n$ is an exponent and $N$ is a number between $1.000...$ and $9.999...$.

Significant Figures

Meaningful digits in a measurement which are known with certainty plus one which is estimated or uncertain.

Precision

The closeness of various measurements for the same quantity.

Accuracy

The agreement of a particular value to the true value of the result.

Law of Conservation of Mass

Proposed by Antoine Lavoisier in 1789, it states that matter can neither be created nor destroyed during physical or chemical changes.

Law of Definite Proportions

Proposed by Joseph Proust, it states that a given compound always contains exactly the same proportion of elements by weight.

Law of Multiple Proportions

Proposed by Dalton in 1803, it states that if two elements combine to form more than one compound, the masses of one element that combine with a fixed mass of the other are in the ratio of small whole numbers.

Gay Lussac’s Law of Gaseous Volumes

States that when gases combine or are produced in a chemical reaction, they do so in a simple ratio by volume, provided all gases are at the same temperature and pressure.

Avogadro’s Law

Proposed in 1811, it states that equal volumes of all gases at the same temperature and pressure should contain equal number of molecules.

Atomic Mass Unit ($amu$)

A mass exactly equal to one-twelfth of the mass of one carbon-12 atom, where $1 \text{ amu} = 1.66056 \times 10^{-24} \text{ g}$.

Molecular Mass

The sum of atomic masses of the elements present in a molecule, obtained by multiplying the atomic mass of each element by the number of its atoms.

Formula Mass

The sum of the atomic masses of all atoms in a formula unit, used for substances like sodium chloride that do not contain discrete molecules.

Avogadro Constant ($N_A$)

The number of entities in one mole, equal to $6.02214076 \times 10^{23} \text{ mol}^{-1}$.

Molar Mass

The mass of one mole of a substance in grams, which is numerically equal to its atomic, molecular, or formula mass in unified mass units ($u$).

Empirical Formula

The simplest whole number ratio of various atoms present in a compound.

Molecular Formula

A formula that shows the exact number of different types of atoms present in a molecule of a compound.

Stoichiometry

Derived from Greek words meaning 'element measure,' it deals with the calculation of masses and volumes of reactants and products in a chemical reaction.

Limiting Reagent

The reactant in a chemical reaction that is present in the least amount and is consumed first, thereby limiting the amount of product formed.

Mass Per Cent

\text{Mass % of an element} = \frac{\text{Mass of that element in the compound} \times 100}{\text{Molar mass of the compound}}

Mole Fraction

The ratio of the number of moles of a particular component to the total number of moles of the solution ($x_A = \frac{n_A}{n_A + n_B}$).

Molarity ($M$)

The number of moles of solute in 1 litre of the solution ($\text{Molarity} = \frac{\text{No. of moles of solute}}{\text{Volume of solution in litres}}$).

Molality ($m$)

The number of moles of solute present in 1 kg of solvent ($\text{Molality} = \frac{\text{No. of moles of solute}}{\text{Mass of solvent in kg}}$).