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Lesson 4.7 • Competencies 4.3, 4.4 & 4.5Interactive Simulation
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Unit 4 Practicals Hub: Virtual Thermal Laboratory

Interactive virtual laboratory investigations for all 6 official NIE syllabus practicals: Boyle’s Law, solid specific heat capacity, latent heat of fusion of ice, latent heat of vaporization of water, Newton’s Law of Cooling, and Searle’s bar thermal conductivity.

Marking a lesson complete represents finishing your study of the topic; it does not denote tested mastery.

Learning Objectives

  • Perform virtual measurements, verify physical equations, and evaluate percentage discrepancies against standard literature values.
  • Master laboratory precautions and error elimination procedures for practical examinations.

Syllabus Topic Outline

Competencies 4.3, 4.4 & 4.5
  • 1Practical 4.1: Boyle’s Law Verification (U-tube Manometer)
  • 2Practical 4.2: Specific Heat of a Solid Metal by Method of Mixtures
  • 3Practical 4.3: Specific Latent Heat of Fusion of Ice
  • 4Practical 4.4: Specific Latent Heat of Vaporization of Steam
  • 5Practical 4.5: Verification of Newton’s Law of Cooling
  • 6Practical 4.6: Thermal Conductivity of Copper by Searle’s Bar

A/L Physics Laboratory: Unit 4 Thermal Physics Practicals Hub

Interactive virtual laboratory investigations covering official NIE A/L Physics syllabus practicals (Exp 22–30) for Unit 4 Thermal Physics.

Practical 4.1: Verification of Boyle’s Law for a Gas

Aim: To verify Boyle’s law (P · V = constant at constant temperature) for a fixed mass of dry air and determine atmospheric pressure graphically.

Boyle’s Law Apparatus Schematic
Closed EndAir (L)Open (Atm H)hP = H + h

P · L = constant at constant temperature (P ∝ 1/L)

Physical Principle & Boyle’s Law

For a fixed mass of an ideal gas at constant temperature, pressure is inversely proportional to volume: P · V = constant ⟹ P ∝ 1 / V Since the closed glass tube has a uniform internal cross-sectional area A, the volume of the trapped air column is directly proportional to its length L (V = A · L): P · L = constant Total absolute pressure P of the trapped air is: P = H + h = H + (y_open - y_closed) where: • H is atmospheric pressure (from Fortin barometer, approx 76.0 cmHg) • h is the difference in mercury meniscus levels between the open and closed tubes Plotting total pressure P against 1/L yields a straight line passing through the origin. Alternatively, plotting difference h against 1/L gives a line with negative intercept -H on the vertical pressure axis.

Atmospheric Barometer H:
cmHg
Experimental Observations (Pressure vs Air Column Length)
TrialOpen Tube Level y₁ (cm)Closed Tube Level y₂ (cm)Difference h (cmHg)Air Length L (cm)Total Pressure P (cmHg)P · L Product (cmHg · cm)
1+20.096.01728.0
2+10.086.01737.2
3+0.076.01748.0
4-10.066.01768.8
5-20.056.01797.6
Mean (P · L) Product:1755.9 cmHg · cm
Max Deviation from Mean:2.37%
Boyle’s Law Verified (P · L Constant Within 3.5%)
Experimental Precautions

1. Raise and lower the mercury reservoir slowly to ensure compression/expansion is strictly isothermal, allowing air temperature to return to room temperature before taking readings. 2. The trapped air must be completely dry, as moisture vaporizes and deviates from ideal gas behavior. 3. Avoid parallax error when aligning with the curved mercury meniscus top.