CHEMISTRY Flashcards
What is Chemistry?
The study of matter, its properties, composition, and the changes it undergoes.
What are the three states of matter?
Solid, Liquid, Gas.
What is the difference between Physical and Chemical Changes?
Physical change alters form without changing composition; chemical change creates new substances.
What are Intensive and Extensive Properties?
Intensive: Independent of amount (e.g., density, boiling point); Extensive: Depends on amount (e.g., mass, volume).
What is an Atom?
The smallest unit of an element that retains its properties.
What are the subatomic particles?
Protons (+), Neutrons (0), Electrons (-).
Where are Protons and Neutrons located?
In the nucleus of the atom.
What is the Periodic Table?
A chart organizing elements by atomic number and properties.
What are Groups and Periods in the Periodic Table?
Groups are vertical columns; Periods are horizontal rows.
What is a Mole?
A quantity representing 6.022 x 10^23 particles of a substance (Avogadro’s number).
What is Molar Mass?
The mass of one mole of a substance, in grams per mole (g/mol).
What is a Chemical Bond?
A force that holds atoms together in compounds.
Types of Chemical Bonds
Ionic (transfer of electrons), Covalent (sharing of electrons), Metallic (free-moving electrons in metals).
What is a Chemical Reaction?
A process where substances change into new substances with different properties.
Types of Chemical Reactions
Synthesis, Decomposition, Single Replacement, Double Replacement, Combustion.
What is the Law of Conservation of Mass?
Mass is neither created nor destroyed in a chemical reaction.
What is a Solution?
A homogeneous mixture of solute (dissolved substance) and solvent (dissolving medium).
What is Solubility?
The ability of a solute to dissolve in a solvent.
What is a Saturated Solution?
A solution where the maximum amount of solute is dissolved.
What is an Unsaturated Solution?
A solution that can still dissolve more solute.
What is a Supersaturated Solution?
A solution that contains more dissolved solute than it normally would at a given temperature.
What happens to solubility when temperature increases?
Solubility of solids increases, solubility of gases decreases.
What happens to solubility when pressure increases?
Solubility of gases increases (Henry’s Law).
What is Miscibility?
The ability of liquids to mix in all proportions (e.g., water and ethanol).
What is Immiscibility?
The inability of liquids to mix (e.g., oil and water).
What is Boiling Point?
The temperature at which a liquid changes to a gas at a given pressure.
What is Ductility?
The ability of a material to be stretched into a wire.
What is Cohesion?
The attraction between molecules of the same substance (e.g., water molecules sticking together).
What is Adhesion?
The attraction between different substances (e.g., water sticking to glass).
What is Surface Tension?
A force that causes the surface of a liquid to contract and resist external force.
What is Brittleness?
The tendency of a material to break or shatter when force is applied.
What is Agitation?
The stirring or shaking of a solution to increase the rate of dissolution.
What is Stirring?
The manual movement of a solution to help dissolve a solute faster.
What is Pressure?
The force exerted per unit area by gas particles colliding with surfaces.
What is Capillary Action?
The ability of a liquid to flow in narrow spaces without external force, due to cohesion and adhesion.
What is Molarity?
A concentration unit defined as moles of solute per liter of solution (mol/L).
What is Molecular Formula?
A formula that shows the actual number of atoms of each element in a molecule.
What is Empirical Formula?
The simplest whole-number ratio of atoms in a compound.
What is Viscosity?
A measure of a liquid’s resistance to flow.
What happens to viscosity when temperature increases?
Viscosity decreases (liquids flow more easily).
What happens to viscosity when temperature decreases?
Viscosity increases (liquids become thicker).
What is Temperature?
A measure of the average kinetic energy of particles in a substance.
What happens to particle movement when temperature increases?
Particles move faster and spread apart.
What happens to particle movement when temperature decreases?
Particles move slower and come closer together.
What happens to gas pressure when volume decreases?
Pressure increases (Boyle’s Law).
What happens to gas pressure when temperature increases?
Pressure increases (Gay-Lussac’s Law).
What is an Acid?
A substance that donates H+ ions and has a pH below 7.
What is a Base?
A substance that donates OH- ions and has a pH above 7.
What is Neutralization?
A reaction between an acid and a base to form water and salt.
What is Stoichiometry?
The calculation of reactants and products in a chemical reaction.
What is the Ideal Gas Law?
PV = nRT, where P = pressure, V = volume, n = moles, R = gas constant, T = temperature.
What is Thermochemistry?
The study of energy changes in chemical reactions.
What is an Exothermic Reaction?
A reaction that releases heat energy.
What is an Endothermic Reaction?
A reaction that absorbs heat energy.
What is an Atom?
The smallest unit of an element that retains its chemical properties.
What is a Molecule?
A group of two or more atoms bonded together.
What is a Substance?
A form of matter with a uniform and definite composition, either an element or a compound.
What are Van der Waals Forces?
Weak intermolecular forces including dipole-dipole interactions and London dispersion forces.
What is a Polar Bond?
A covalent bond where electrons are shared unequally, creating a dipole moment.
What is a Non-Polar Bond?
A covalent bond where electrons are shared equally between atoms.
What is an Ionic Bond?
A bond formed by the transfer of electrons from a metal to a non-metal, creating charged ions.
What is a Covalent Bond?
A bond formed by the sharing of electrons between two non-metal atoms.
How do Van der Waals forces affect boiling points?
Stronger Van der Waals forces increase boiling points due to higher intermolecular attraction.
What is the difference between Polar and Non-Polar Molecules?
Polar molecules have an uneven charge distribution, while non-polar molecules have an even charge distribution.
