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Specific Heat. What is the specific heat of H2O? Write the equation for measuring specific heat: Which has a higher specific heat value, sand or water? Use your answer to explain why a sandbox is hotter than a swimming pool on a hot summer day. Calculations: Example: An 85 g piece of copper is heated from 30°C to 45°C.
Specific heat – the quantity of energy needed to increase the temperature of one gram of a substance by 1 K or 1 oC. Unique substances have unique specific heats. Ex) Specific heat of liquid water is 4.18 J/(g·K) Formula for Heat: Q = m • Cp • ∆T. Q = heat . m = mass. Cp = specific heat. ∆T = Tfinal — Tinitial = change in temperature. Units:
The symbol c stands for specific heat and depends on the material and phase. The specific heat is the amount of heat necessary to change the temperature of 1.00 kg of mass by 1.00ºC. The specific heat c is a property of the substance; its SI unit is J/(kg⋅K) or J/(kg⋅C).
Heat capacity of crystalline solids. Heat capacity is the increment in energy required to change the temperature of some quantity of matter. Experiments show that CV depends on temperature, in general. CV ~ T3 as T → 0. Figure on right is the heat capacity of diamond.
Specific Heat (cs): The quantity of heat liberated or absorbed when the temperature of 1.00 gram of a substance falls or rises 1.00 C. Specific heat is temperature (and phase) dependent. Thus, one must know not only the substance but also the temperature range and whether a solid, liquid or gas is involved.
The SI unit for specific heat is \(J/(kg \times K)\) or \(J/(kg \times ^oC)\). (Recall that the temperature change \(\Delta T\) is the same in units of kelvin and degrees Celsius.) Values of specific heat must generally be measured, because there is no simple way to calculate them precisely.
The formula used is: (q = energy change) (m = mass) (c = specific heat capacity) (∆T = temperature change) Example 1: How much energy is needed to change the temperature of 60.0 g of water by 15.0 °C. Step 1: Input the values into the formulae. (Specific heat capacity = 4.18 Jg -1 K -1 ) ⇒ q = 60 x 4.18 x 15 = 3762 J
