Calorimetry Thermochemistry pt 2 Calorimetry Measure of heat

Calorimetry Thermochemistry pt 2

Calorimetry Measure of heat flow

Heating different objects If all these objects gain the same amount of heat, will they all be the same temperature?

The temperature change of an object when specific amount of heat absorbed is determined by HEAT CAPACITY (c) Heat required to raise temp of object by 1 K (or 1°C)

Specific Heat Capacity (often referred to as Specific Heat, cs) Amount of energy required to raise the temperature of 1 g of object by 1 K (or 1°C) J/g-K J/g-°C The ΔT in Kelvin is equal to ΔT in Celsius

q = mcΔT heat mass Specific heat Change in temp Look at specific heat chart, if all substances were given the same quantity of heat, which would undergo the greatest temperature change?

Sample: a)How much heat is needed to warm 250 g of water from 22°C to 98°C? b) What is the molar heat capacity of water?

STO P

Calorimeter Device used to measure heat flow Coffee cup calorimeter Reactio n constan occurs unde r t press ure (fro atmosp m here) • Reactants and products are system • Water (solvent) which they are dissolved in is part of surroundings

Coffee cup calorimeter Heat transfer between system (reactants+products) and surroundings (water from soln) System is exothermic, what happens to temp of solution? TEMP INCREASES System is endothermic, what happens to temp of solution? TEMP DECREASES