General Chemistry 1 – Matter, Measurement & Properties

Course Structure & Assessment

WW/PT (Written Work / Performance Task) weightings

• WW 1 (8.33 %)

• WW 1.1 (4.165 %): Measurements, Matter, Worksheet (prep for PT 1.2)

• WW 1.2 (4.165 %): Quiz (Week 3)

• PT 1 (15 %)

• PT 1.1: Labster simulation (individual, online)

• PT 1.2: Basic Laboratory Skills (face-to-face, Week 4)

• QA / Mid-term Exam (10 %) – Week 9

Units & Unit Conversion

Derived-Unit Conversions (Dimensional Analysis)

• Square & cubic units: apply the power to each conversion factor

  • Example: $36.9\,\text{cm}^2\left(\frac{0.01\,\text{m}}{1\,\text{cm}}\right)^2=0.00369\,\text{m}^2$

• Density‐type units

  • $0.85\,\frac{\text{g}}{\text{mL}}\left(\frac{1000\,\text{mL}}{1\,\text{L}}\right)=850\,\text{g}\,/\,\text{L}$

• Speed

  • $25\,\frac{\text{m}}{\text{s}}\left(\frac{1\,\text{km}}{1000\,\text{m}}\right)\left(\frac{3600\,\text{s}}{1\,\text{h}}\right)=90\,\text{km}\,/\,\text{h}$

Temperature Scales & Conversions

• Celsius ↔ Fahrenheit

  • $\frac{9}{5}F = C + 32 \qquad \text{or} \qquad C=\frac{5}{9}(F-32)$

• Celsius ↔ Kelvin

  • $K=C+273.15 \qquad \text{or} \qquad C=K-273.15$

• Worked examples

  • $212^{\circ}F \Rightarrow C = \tfrac{5}{9}(212-32)=100^{\circ}C$

  • $37.5^{\circ}C \Rightarrow F = \tfrac{9}{5}(37.5)+32=99.5^{\circ}F$

  • $375\,K \Rightarrow C = 375-273.15=101.85^{\circ}C$

Learning Outcomes (Course Outcome 1)

• Differentiate states of matter

• Identify physical vs chemical properties

• Classify matter by composition

• Describe & apply separation techniques

• Distinguish precision vs accuracy

• Use significant figures correctly

• Determine liquid & solid density

Particulate Nature of Matter

Kinetic-Molecular Theory (KMT)

• Matter is composed of tiny particles (atoms, molecules, ions) in perpetual motion.

• Inter-particle forces allow structure or fluid flow; magnitude: gas < liquid < solid.

• Properties of each state stem from these forces.

• Temperature ↑ ⇒ particle speed ↑ (energy proportional to T).

States of Matter

• Solid: definite shape/volume, tightly packed, incompressible, high density.

• Liquid: no fixed shape, definite volume, nearly incompressible, medium density.

• Gas: fills container, widely spaced, highly compressible, low density.

Properties of Matter

Physical Properties (no composition change)

• Mass, volume, density, state, melting pt, boiling pt, solubility

• Hardness, color, odor, malleability, ductility, luster, opacity, viscosity

Chemical Properties (composition change potential)

• Reactivity, flammability, toxicity, corrosiveness, radioactivity, stability

Intensive vs Extensive

• Intensive (independent of amount): boiling pt, density, color, etc.

• Extensive (dependent on amount): mass, volume, length, etc.

Accuracy & Precision

• Accuracy: closeness to true value

• Precision: reproducibility / closeness of a set of values

Significant Figures

• Non-zero digits & trapped zeros always significant.

• Leading zeros never; trailing zeros significant if decimal is present.

• Calculation rules: ×/÷ (fewest sig-figs), +/− (fewest decimal places).

Changes in Matter

• Physical Change: no new substance (melting ice, boiling water, dissolving salt).

• Chemical Change: new substances formed (burning wood, rusting, fermentation).

Seat-work examples with keys

• Campfire – chemical

• Dissolving CuSO₄ – physical

• Photosynthesis – chemical

• Melting gold – physical

Classification of Matter

Pure Substances

• Elements: one type of atom (Na, Hg, diamond – (C)).

• Compounds: fixed ratio of different elements (CO₂, CF₄, NaHCO₃, C₂H₆O).

Mixtures

• Variable composition; can be separated physically.

Homogeneous (Solutions)

• Uniform; single phase; <1 nm particles; no Tyndall.

• Components: solute (smaller amount) + solvent (greater amount).

Heterogeneous

• Non-uniform; visible phases.

  • Suspension: >1000 nm, settles, filterable (muddy water).

  • Colloid: 1–1000 nm, no settling, scatters light (milk, smoke).

Mixture identification keys

• Gasoline, stainless steel, vodka – homogeneous.

• Blood, salad, mixed nuts – heterogeneous.

Methods of Separating Mixtures

• Decantation – pours off supernatant; relies on density.

• Filtration – porous barrier traps solids (sand + water).

• Evaporation – removes volatile solvent; leaves solid residue (salt solution).

• Distillation – exploits different boiling points; vapor → condense to distillate.

• Sublimation – one solid sublimes (NH₄Cl from sand).

• Chromatography – mobile phase carries components across stationary phase; separates by adsorption & solubility.

Measurement-Related Concepts

• Scientific Notation: (N\times10^{n}) where (1\le N<10).

• Dimensional Analysis: multiply by unity factors to convert units systematically.

• Density ((\rho)): $\rho = \frac{m}{V}$ typically g/cm³ (solids) or g/mL (liquids).

Worked Exercise Sets (from seat-work)

Property Type Identification (answers)

1. Ammonia colourless gas (STP) – Physical

2. Ethanol freezing pt – Physical

3. Magnetite crystal system – Physical

4. Diamond oxidizes at high T – Chemical

5. Na + alcohol → alkoxide + H₂ – Chemical

Change Type Identification (answers)

A. Campfire logs – Chemical
B. Baking cake batter – Chemical
C. Dissolving CuSO₄ – Physical
D. Photosynthesis – Chemical
E. Melting & molding gold – Physical
F. Grapes → wine – Chemical
G. Digestion – Chemical

Substance Classification (answers)

• Elements: Hg, Na, diamond

• Compounds: CF₄, NaHCO₃ (baking soda), CO₂ (dry ice), C₂H₆O (ethanol)

• Mixtures: 18-karat gold, 90 % isopropyl alcohol, air, milk, soil, gel, steel, vinegar

Reference Texts

• Bayquen & Peña, Exploring Life Through Science (2018)

• Jurs, Moore, Stanitski, General Chemistry 1 (2017)

• Kotz et al., Chemistry & Chemical Reactivity 9e (2015)

• Silberberg & Amateis, Chemistry 9e (2021)