MCC RT101-F01 Final 2025

Difference between heat and temperature?

Heat is energy transfer; temperature measures hotness or coldness.

Heat capacity vs. specific heat?

Heat capacity = energy to raise temp 1 °C; specific heat = energy per unit mass.

3 ways heat is transferred?

Conduction, convection, radiation.

Is evaporation endothermic or exothermic?

Endothermic

Condensation is what type of process?

Exothermic (releases energy).

What is cohesion?

like attraction

What is adhesion?

unlike molecules attract

What causes surface tension and what shape does it create?

Cohesive forces make liquids form spheres (minimal surface area).

Four main gas variables?

Pressure (P), volume (V), temperature (T), amount (n).

Boyle’s Law formula & relationship?

P₁V₁ = P₂V₂ → inverse relationship (P ↑ → V ↓).

Charles’s Law formula & condition?

V₁/T₁ = V₂/T₂ → constant pressure.

Gay-Lussac’s Law formula & condition?

P₁/T₁ = P₂/T₂ → constant volume.

Henry’s Law summary?

Gas dissolves in liquid in proportion to pressure above the liquid.

Dalton’s Law summary?

Total pressure = sum of all partial pressures.

Why must 47 mmHg be subtracted when calculating alveolar PO₂?

It represents water vapor pressure; ignoring it overestimates O₂.

Clinical example of Boyle’s Law?

During inhalation, lung volume ↑ → pressure ↓ → air flows in.

Why is a gas cylinder dangerous in heat?

Gay-Lussac’s Law—pressure rises with temperature and may rupture.

How does hyperbaric O₂ therapy help wounds?

Henry’s Law—higher pressure dissolves more O₂ into blood/tissues.

Define vapor pressure.

Pressure exerted by water vapor

Hot air can hold more water vapor- True or False

True

Define absolute humidity and its clinical target.

Mass of H₂O vapor per L of gas; 43.8 mg/L at 37 °C and 760 mmHg.

Define relative humidity.

Ratio of actual water vapor to saturation amount, expressed %.

What is dew point?

Temperature where air becomes saturated (100 % RH).

Explain evaporation vs. condensation in energy terms.

Evaporation = energy absorbed; condensation = energy released.

Alveolar air equation formula?

PAO₂ = (Pb − 47) × FIO₂ − (PaCO₂ × 1.25).

Why monitor condensation in ventilator tubing?

Ensures gases are fully humidified at 100 % RH to protect lungs.

Why maintain 100 % RH for inspired gases?

Prevents airway drying and thickened secretions.

How does temperature affect relative humidity?

Warm air holds more vapor → RH drops; cold air → RH rises.

Water vapor’s role in the hydrologic cycle?

Evaporation → condensation → precipitation; mirrors humidification in care.

Define laminar flow.

Smooth, parallel layers; linear pressure–flow relationship.

Define turbulent flow.

Chaotic flow with eddies; pressure ↑ exponentially with flow.

Poiseuille’s Law: what variable most affects resistance?

Radius (r); R ∝ 1/r⁴.

Bernoulli’s Principle summary.

Faster flow → lower pressure.

Venturi Effect definition.

Pressure drop as fluid passes through a narrow constriction.

Coanda Effect definition.

Fluid jet sticks to and follows a curved surface.

Where is laminar flow found in airways?

Small peripheral bronchioles.

Where is turbulent flow common?

Large airways (trachea).

What is the Reynolds number used for?

Predicts laminar vs turbulent flow.

Two factors that increase turbulence?

Higher velocity and larger diameter.

Water vapor pressure at 37 °C?

47 mmHg.

Absolute humidity at 37 °C?

43.8 mg/L.

F to C

(° F − 32) / 1.8

C to F

(1.8 *°C )+ 32

C to K

C + 273

1 ATM to TORR

760 TORR

1 ATM to mmHg

760 mmHg

1 ATM to cmH2O

1034 H2O

1 ATM to PSI

14.7 PSI

1 ATM to cmHg

76 cmHg

How many L does a Mole of any ideal gas occupies? 

22.4 L at STP

Deposition

Direct conversion for a gas to a solid

Sublimation

solid to gas

formula for RH

%RH = Content (Absolute Humidity)/Saturated Capacity × 100

Avogadro’s Formula for gas density 

(g/mol) / 22.4 (L/mol)