HS1 Physics1

Heat Capacity

Practice Problem

How much energy does it take to boil a 100g ice cube?

(The ice cube starts at 0°C)

source

l_{fusion} = 0.334\ \dfrac{kJ}{kg}\\ l_{vapor} = 2.260\ \dfrac{kJ}{kg}\\ Q = m \cdot l

c_{ice} = 2.108\ \dfrac{kJ}{kgC}\\ c_{water} = 4.187\ \dfrac{kJ}{kgC}\\ c_{steam} = 1.996\ \dfrac{kJ}{kgC}\\ Q = m \cdot c \Delta T

Practice Problem

l_{fusion} = 0.334\ \dfrac{kJ}{kg}\\ l_{vapor} = 2.260\ \dfrac{kJ}{kg}\\ Q = m \cdot l

c_{ice} = 2.108\ \dfrac{kJ}{kgC}\\ c_{water} = 4.187\ \dfrac{kJ}{kgC}\\ c_{steam} = 1.996\ \dfrac{kJ}{kgC}\\ Q = m \cdot c \Delta T

Q \rightarrow \text{Heat} \\ m \rightarrow \text{mass} \\ l \rightarrow \text{latent heat} \\ c \rightarrow \text{specific heat} \\ \Delta T \rightarrow \text{Change in temperature}

Solid to Liquid

source

l_{fusion} = 0.334\ \dfrac{kJ}{kg}\\ Q = m \cdot l_{fusion}

①

0.1kg ice cube

Q_{s \rightarrow l} = 0.1kg \cdot 0.334\ \dfrac{kJ}{kg} = 0.0334\ kJ

Liquid to Gas

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l_{vapor} = 2.260\ \dfrac{kJ}{kg}\\ Q = m \cdot l_{vapor}

①

②

0.1kg of water

Q_{l \rightarrow g} = ①\ +\ ② = 41.87\ kJ + 0.226\ kJ

②

①

c_{water} = 4.187\ \dfrac{kJ}{kg}　\\ Q = m \cdot c_{water} \cdot \Delta T

Practice Problem

How much energy does it take to boil a 100g ice cube?

(The ice cube starts at 0°C)

source

Q_{s \rightarrow l} = 0.211\ kJ

Q_{l \rightarrow g} = 42.096\ kJ

Q = 42.307