Orientation

Question 1

Intra-

Answer 1

Definition: Within
Example Usage: Intramolecular bonding occurs within a molecule.

Question 2

Inter-

Answer 2

Definition: Between
Example Usage: Intermolecular bonding takes place between molecules.

Question 3

**

Metallic Bonding

Answer 3

Definition: Bonding within metals, where cations are held together by a sea of delocalized electrons.
Example Usage: Metallic bonding is unique to metals.

Question 4

Covalent Bonding

Answer 4

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.

Question 5

Ionic Bonding

Answer 5

Definition: Bonding between a metal (cation) and a non-metal (anion) with an electrostatic attraction.
Example Usage: Sodium chloride (NaCl) exhibits ionic bonding.

Question 6

Hydrogen Bonding

Answer 6

Definition: The strongest intermolecular force, occurring between hydrogen and highly electronegative atoms (F, O, N).
Example Usage: Water molecules are connected by hydrogen bonding.

Question 7

Dipole-Dipole Forces

Answer 7

Definition: Forces between molecules with opposite poles, involving δ+ and δ- charges.
Example Usage: Dipole-dipole forces contribute to the properties of polar compounds.

Question 8

Dispersion Forces

Answer 8

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.

Question 9

Chemical Symbol

Answer 9

Definition: Representation of each element, found on the Periodic Table.
Example Usage: “O” is the chemical symbol for oxygen.

Question 10

Chemical Formula

Answer 10

Definition: Expression of the ratio of atoms or ions in a compound.
Example Usage: H2O is the chemical formula for water.

Question 11

Valency

Answer 11

Definition: The combining capacity of an element.
Example Usage: The valency of sodium is +1.

Question 12

Ionic Formulas

Answer 12

Definition: Representation of the ratio of positive and negative ions in an ionic compound.
Example Usage: The formula for sodium hydroxide is NaOH.

Question 13

Combustion Reactions

Answer 13

Definition: Reactions resulting in the complete combustion of a substance.
Example Usage: Methane combustion: CH4 + 2O2 → CO2 + 2H2O.

Question 14

Decomposition Reactions

Answer 14

Definition: Reactions where one compound breaks down into other compounds or elements.
Example Usage: Decomposition of calcium carbonate: CaCO3 → CaO + CO2.

Question 15

Acid and Base Reactions (Neutralisation Reactions)

Answer 15

Definition: Reactions between acidic and basic compounds.
Example Usage: Neutralization of hydrochloric acid and sodium hydroxide: HCl + NaOH → NaCl + H2O.

Question 16

Solubility Rules

Answer 16

Definition: Guidelines determining the solubility of compounds based on anions and cations.
Example Usage: Most chlorides are soluble, except AgCl, HgCl2, and PbCl2.

Question 17

Mole

Answer 17

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.

Question 18

Avogadro’s Number

Answer 18

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.

Question 19

Molar Mass

Answer 19

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.

Question 20

Molarity (c)

Answer 20

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.

Question 21

Amount of Substance (n)

Answer 21

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.

Question 22

Relationship Between Amount and Mass

Answer 22

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.

Question 23

Concentration of Ions

Answer 23

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.

Question 24

Ideal Gas Equation (PV = nRT)

Answer 24

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.

Question 25

Molar Gas Volume

Answer 25

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.

Question 26

Significant Figures

Answer 26

Definition: Digits in a measured quantity that contribute to its precision, including certain rules for zeros.
Example Usage: 34.20 has four significant figures.

Question 27

Rounding Off

Answer 27

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.

Question 28

Precision and Calculations

Answer 28

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.

Question 29

Avogadro’s Number

Answer 29

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.

Question 30

Mass/Mass Percentage (% m/m)

Answer 30

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%.

Question 31

Mass/Volume Percentage (% m/v)

Answer 31

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%.

Question 32

Volume/Volume Percentage (% v/v)

Answer 32

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%.

Question 33

Parts Per Million (ppm)

Answer 33

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.

Question 34

Parts Per Billion (ppb)

Answer 34

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.

Question 35

Correct Units

Answer 35

Ensure using correct units for % m/m, % m/v, and % v/v (all mass in grams, volumes in mL).

Question 36

Significant Figures

Answer 36

Match the final answer’s significant figures to those in the question.

Question 37

Significant Figures

Answer 37

Definition: Digits in a measured quantity that contribute to its precision, including certain rules for zeros.
Example Usage: 34.20 has four significant figures.

Question 38

Rounding Off

Answer 38

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.