Name: Callie Archibald
Partner: Coral Hutchinson
Formal Laboratory Report
C125 Experimental Chemistry I
October 21, 2012
In chemistry it is often necessary to determine how energy moves. Each substance
has a heat capacity. When substances react energy is either absorbed or released in the
form of heat. If the energy is absorbed we say that the reaction is endothermic and if
energy is released the reaction is exothermic.
In thermodynamics “energy and its changing forms” 1 are studied. To find the heat
of a reaction, a simple device called a calorimeter is used. By using this device and taking
measurements of mass temperature the heat of a reaction can be determined.
∆H rxn = -(C calorimeter +C contents ) ∆T
Eq. 1 shows that when the specific heat of a calorimeter is added to the specific heat of
the contents of the calorimeter, then multiplied by the change in temperature, the heat of
the reaction can be determined.
In order to find the heat of the reaction, first C (heat capacity) has to be found.
The C variable is the heat capacity for each substance. C must be calculated for both the
calorimeter and its contents.
C = (C SH ) x (mass of the substance)
Eq. 2 shows that when the C SH (specific heat) of a substance is multiplied by the mass of
the substance, then C (heat capacity) can be found.
The second variable we need to find it the change in temperature (∆T).
∆T = T f - T i
Eq. 3 shows that when the ∆T (change in termperature) can be found by subtracting the
initial temperature (T i ) from the final temperature (T f ).
For part I, a calorimeter was constructed using a beaker, two Styrofoam cups,
cardboard, a rubber stopper, and a thermometer. 50.0 mL of water from the carboy was
placed in the calorimeter, and then allowed to reach temperature equilibrium. 50.0 mL of
water from the carboy was heated until 40C° warmer than room...