Orientation Flashcards
Intra-
Definition: Within
Example Usage: Intramolecular bonding occurs within a molecule.
Inter-
Definition: Between
Example Usage: Intermolecular bonding takes place between molecules.
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Metallic Bonding
Definition: Bonding within metals, where cations are held together by a sea of delocalized electrons.
Example Usage: Metallic bonding is unique to metals.
Covalent Bonding
Definition: Bonding between non-metals involving the sharing of electrons to achieve full outer shells.
Example Usage: Covalent bonding is common in molecules formed by non-metal elements.
Ionic Bonding
Definition: Bonding between a metal (cation) and a non-metal (anion) with an electrostatic attraction.
Example Usage: Sodium chloride (NaCl) exhibits ionic bonding.
Hydrogen Bonding
Definition: The strongest intermolecular force, occurring between hydrogen and highly electronegative atoms (F, O, N).
Example Usage: Water molecules are connected by hydrogen bonding.
Dipole-Dipole Forces
Definition: Forces between molecules with opposite poles, involving δ+ and δ- charges.
Example Usage: Dipole-dipole forces contribute to the properties of polar compounds.
Dispersion Forces
Definition: The weakest intermolecular forces, resulting from temporary dipoles induced by electron positions.
Example Usage: Dispersion forces are present in all molecules but are usually very weak.
Chemical Symbol
Definition: Representation of each element, found on the Periodic Table.
Example Usage: “O” is the chemical symbol for oxygen.
Chemical Formula
Definition: Expression of the ratio of atoms or ions in a compound.
Example Usage: H2O is the chemical formula for water.
Valency
Definition: The combining capacity of an element.
Example Usage: The valency of sodium is +1.
Ionic Formulas
Definition: Representation of the ratio of positive and negative ions in an ionic compound.
Example Usage: The formula for sodium hydroxide is NaOH.
Combustion Reactions
Definition: Reactions resulting in the complete combustion of a substance.
Example Usage: Methane combustion: CH4 + 2O2 → CO2 + 2H2O.
Decomposition Reactions
Definition: Reactions where one compound breaks down into other compounds or elements.
Example Usage: Decomposition of calcium carbonate: CaCO3 → CaO + CO2.
Acid and Base Reactions (Neutralisation Reactions)
Definition: Reactions between acidic and basic compounds.
Example Usage: Neutralization of hydrochloric acid and sodium hydroxide: HCl + NaOH → NaCl + H2O.
Solubility Rules
Definition: Guidelines determining the solubility of compounds based on anions and cations.
Example Usage: Most chlorides are soluble, except AgCl, HgCl2, and PbCl2.
Mole
Definition: A unit representing the amount of substance containing Avogadro’s number (6.02 x 10^23) of entities.
Example Usage: One mole of carbon atoms contains 6.02 x 10^23 carbon atoms.
Avogadro’s Number
Definition: The number of entities (atoms, molecules, ions, etc.) in one mole, equal to 6.02 x 10^23.
Example Usage: Avogadro’s number is crucial for understanding the scale of chemical quantities.
Molar Mass
Definition: The mass of one mole of a substance, measured in grams per mole (g/mol).
Example Usage: The molar mass of water (H2O) is approximately 18.02 g/mol.
Molarity (c)
Definition: The concentration of a solute in a solution, expressed as moles of solute per liter of solution (mol/L).
Example Usage: A solution with a molarity of 0.5 mol/L contains 0.5 moles of solute in each liter of solution.
Amount of Substance (n)
Definition: The quantity of solute present in a sample, measured in moles (mol).
Example Usage: The amount of substance in a solution can be determined using the formula n = cV.
Relationship Between Amount and Mass
Definition: The formula n = m/M relates the amount of substance (moles) to the mass and molar mass.
Example Usage: To find the number of moles, use n = m/M, where m is the mass and M is the molar mass.
Concentration of Ions
Definition: If the concentration of a compound is known, the concentration of ions produced in solution can be determined.
Example Usage: In NaCl, the concentration of Na+ ions is the same as the concentration of NaCl.
Ideal Gas Equation (PV = nRT)
Definition: The general gas equation relating pressure, volume, temperature, and moles of gas for ideal gases.
Example Usage: PV = nRT is used to calculate the behavior of gases under different conditions.
Molar Gas Volume
Definition: The volume of one mole of any gas at standard temperature and pressure (STP).
Example Usage: The molar gas volume at STP is approximately 24.8 L.
Significant Figures
Definition: Digits in a measured quantity that contribute to its precision, including certain rules for zeros.
Example Usage: 34.20 has four significant figures.
Rounding Off
Definition: Determining the appropriate number of significant figures when rounding a calculated value.
Example Usage: Rounding 10.9847 to four significant figures results in 10.98.
Precision and Calculations
Definition: The number of significant figures in a calculated answer is determined by the least precise value in the calculation.
Example Usage: In a calculation involving measurements, the answer should be rounded to match the least precise measurement.
Avogadro’s Number
Definition: The number of entities (atoms, molecules, ions, etc.) in one mole, equal to 6.02 x 10^23.
Example Usage: Avogadro’s number is crucial for understanding the scale of chemical quantities.
Mass/Mass Percentage (% m/m)
Formula:
Mass/Mass Percentage = Mass of Solute / Total Mass of Solution ×100%
Example: For a solution with 6.0508g solute and 110.605g solvent, the % m/m is 5.4706%.
Mass/Volume Percentage (% m/v)
Formula:
Mass/Volume Percentage = Mass of Solute/ Volume of Solution × 100%
Example: Dissolving 289.15g of Ca(N3)2 in 762.5 mL water gives a % m/v of 37.92%.
Volume/Volume Percentage (% v/v)
Formula:
Volume/Volume Percentage =
Volume of Solute/Total Volume of Solution ×100%
Example: Having 25.0 mL of alcohol in a 100 mL solution results in a % v/v of 25.0%.
Parts Per Million (ppm)
Formula:
ppm
=
Mass of Solute (g) / 10^6 g of solution
Example: If a solution has 2.00g substance in 5000g total mass, the concentration is in ppm.
Parts Per Billion (ppb)
Formula:
ppb = Mass of Solute (g) / 10^9 g of solution
Example: For a pollutant present as 3 μg in 500 mL water, the concentration is in ppb.
Correct Units
Ensure using correct units for % m/m, % m/v, and % v/v (all mass in grams, volumes in mL).
Significant Figures
Match the final answer’s significant figures to those in the question.
Significant Figures
Definition: Digits in a measured quantity that contribute to its precision, including certain rules for zeros.
Example Usage: 34.20 has four significant figures.
Rounding Off
Definition: Determining the appropriate number of significant figures when rounding a calculated value.
Example Usage: Rounding 10.9847 to four significant figures results in 10.98.
