A Journey through States of Water – Formula & Equation Sheet
Essential formulas and equations from Curiosity, tailored for Class 6 in Science.
This one-pager compiles key formulas and equations from the A Journey through States of Water chapter of Curiosity. Ideal for exam prep, quick reference, and solving time-bound numerical problems accurately.
Key concepts & formulas
Essential formulas, key terms, and important concepts for quick reference and revision.
Formulas
Q = mcΔT
Q represents heat energy (in joules), m is the mass (in kg), c is the specific heat capacity (in J/kg·°C), and ΔT is the change in temperature (in °C). This formula predicts the heat transferred when a substance changes its temperature, applied when heating or cooling water.
Melting Point of Ice = 0°C
This is the temperature at which ice changes to liquid water. It is critical in understanding phase changes in water.
Freezing Point of Water = 0°C
The temperature at which water solidifies into ice. This point is essential for studying water's state changes.
Boiling Point of Water = 100°C
This is the temperature at which water transitions from liquid to gas. It plays a crucial role in understanding evaporation and steam formation.
Evaporation Rate (vapor pressure)
The tendency of water to vaporize at any temperature. Factors influencing it include temperature, surface area, and air movement.
condensation point varies with pressure
The temperature at which water vapor condenses into liquid. Higher pressures increase condensation temperature.
m = ρV
m is mass (kg), ρ is density (kg/m³), and V is volume (m³). This formula is used for finding mass when volume and density are given.
Density of Water = 1 g/cm³
A key property that describes how much mass is contained in a given volume of water, foundational for understanding buoyancy.
Heat of vaporization = 2260 J/g
The amount of energy required to convert water from liquid to vapor without changing its temperature. This concept is essential in understanding evaporation.
Heat of fusion = 334 J/g
The energy needed to change water from solid (ice) to liquid (water) at the melting point, relevant during phase changes.
Equations
Water Cycle: Evaporation + Condensation + Precipitation
This equation represents the continuous movement of water within the Earth and atmosphere, essential for understanding weather patterns.
Q_condensation = mL
Q_condensation is the heat released during condensation (in joules), m is mass (in kg), and L is the latent heat of vaporization. This equation is crucial for calculations involving heat transfer during state changes.
Pressure Change: P1V1 = P2V2 (For constant temperature)
P1 and V1 are initial pressure and volume, while P2 and V2 are final pressure and volume. This equation relates to gas behavior in water vapor states, derived from Boyle's Law.
Ideal Gas Law: PV = nRT
P is pressure, V is volume, n is the number of moles of gas, R is the gas constant, and T is temperature in Kelvin. This equation links temperature and pressure of water vapor.
R = ΔH/T
Where R is the rate of phase change, ΔH is the heat of phase change, and T is temperature in Kelvin. Useful in analyzing phase changes and energy transfers in water.
Rate of Evaporation = kA(T_s - T_a)
k is a constant, A is the surface area, T_s is surface temperature, and T_a is ambient temperature. This equation shows factors affecting evaporation rates.
Heat Transfer: Q = UΔT
Q is the heat transferred, U is the overall heat transfer coefficient, and ΔT is the change in temperature. This equation is relevant for heating or cooling water processes.
Density of Water: ρ = m/V
Where ρ is density, m is mass in grams, and V is volume in cm³. This relationship helps understand water's buoyancy and state conversions.
Latent Heat Equation: Q = mL_f (for fusion)
Q is heat involved, m is mass (in kg), and L_f is latent heat of fusion. It calculates energy required for melting ice.
Latent Heat Equation: Q = mL_v (for vaporization)
Q is heat involved in vaporization, m is mass (in kg), and L_v is latent heat of vaporization. This equation calculates energy for converting water to vapor.
