Class 11 Chemistry - Chapter 1: Some Basic Concepts of Chemistry

Comprehensive vocabulary flashcards covering basic chemistry concepts, measurement units, scientific laws, and chemical formulas based on the provided Class 11 Chemistry notes.

Chemistry

The branch of science that deals with the composition, structure, properties, and transformations of matter.

Matter

Anything that occupies space and has mass.

Physical Properties

Properties observed without changing the chemical composition of a substance, such as colour, density, melting point, and boiling point.

Chemical Properties

Properties observed when a substance undergoes a chemical change, such as burning, rusting, and reaction with acids.

Accuracy

The closeness of a measured value to the true value.

Precision

The closeness of repeated measurements to each other.

Significant Figures

Digits that are known with certainty plus one uncertain digit.

Scientific Notation

A way to express large or small numbers in the form $a \times 10^n$, where 1 \text{ } \b{

Law of Conservation of Mass

Given by Antoine Lavoisier, it states that mass can neither be created nor destroyed during a chemical reaction.

Law of Definite Proportions

Given by Joseph Proust, it states that a chemical compound always contains the same elements in a fixed proportion by mass.

Law of Multiple Proportions

Given by John Dalton, it states that when two elements form more than one compound, the masses that combine do so in a simple whole-number ratio.

Atomic Mass Unit (u)

A unit of mass defined as exactly $\frac{1}{12}$ the mass of one carbon-12 atom.

Mole

The amount of substance containing $6.022 \times 10^{23}$ elementary entities such as atoms, molecules, or ions.

Avogadro Constant ($N_A$)

Named after Amedeo Avogadro, it is given as $6.022 \times 10^{23} \text{ } mol^{-1}$.

Molar Mass

The mass of one mole of a substance, expressed in units of $g \text{ } mol^{-1}$.

Empirical Formula

A formula representing the simplest whole-number ratio of the atoms of different elements present in a compound.

Molecular Formula

A formula showing the actual number of atoms of each element present in one molecule of a compound.

Stoichiometry

The study of the quantitative relationships between reactants and products in a balanced chemical equation.

Molarity (M)

The number of moles of solute divided by the volume of the solution in L ($mol \text{ } L^{-1}$).

Mole Fraction (x)

The ratio of the moles of a specific component to the total moles of all components in a mixture.

Mass Percentage

Calculated as $(\frac{\text{Mass of solute}}{\text{Mass of solution}}) \times 100$.

STP (Standard Temperature and Pressure)

Conditions defined as a temperature of $273 \text{ } K$ (0^\b{\textdegree}C) and a pressure of $1 \text{ } atm$ ($760 \text{ } mm \text{ } Hg$).

Molar Volume of Gas at STP

The volume occupied by 1 mole of any gas at STP, which is equal to $22.4 \text{ } L$.