The specific heat (C) is the quantity of heat required to raise the temperature of one gram of a substance by one degree Celsius or Kelvin. A calorimeter constant is a constant that measures the heat capacity of the calorimeter. It is calculated by applying a known amount of the heat and determining the resultant change in temperature in the calorimeter

1. SHREE MALLIKARJUN COLLEGE CLASS:FYBSC
SAFETY: Refer to the MSDS of mercury.
-Dr. Mithil S. FalDesai
Aim: To determine the heat capacity of the calorimeter.
Chemicals: Distilled water.
Apparatus/Instrument: thermometer, calorimeter
Theory: The specific heat (C) is the quantity of heat required to raise the temperature of one
gram of a substance by one degree Celsius or Kelvin. A calorimeter constant is a constant that
measures the heat capacity of the calorimeter. It is calculated by applying a known amount of the
heat and determining the resultant change in temperature in the calorimeter.
Heat lost by water (-qhot)= heat gained by cold water (qcold) + heat gained by the calorimeter (qcal)
qcal= -qhot - qcold --------------eq 1
The negative sign of qhot indicates that the heat is lost by hot water. The quantity of heat
absorbed by calorimeter can be determined by measuring the amount of water in calorimeter and
change in temperature.
qhot= m1 X specific heat of water X Δthot; where Δthot = T3-T2 --------------eq 2
qcold= m2 X specific heat of water X Δtcold; where Δtcold = T3-T1 --------------eq 3
Specific heat of water is 4.184 J g-1◦C-1and ‘m1’ and ‘m2’ is the mass in gram of hot and cold
water respectively. The T1, T2 and T3 are temperatures of water at room temperature, hot water
and, resultant the temperature after mixing cold and hot water in the calorimeter, respectively.
The heat capacity of calorimeter, Ccal, is the quantity of heat absorbed by the calorimeter for
every one degree rise in temperature of reaction and can be determined by the following formula.
Ccal = (qcal/ Δtcold) + 4.184 in J g-1◦C-1 X (m1+ m2) in g --------------eq 4
The unit of heat capacity is J ◦C-1.
Procedure:
1) Take 50 ml distilled water in the calorimeter, wait for 30 min so that distilled water attains
room temperature.
2) Measure the room temperature of this 50 mL water (T1)
3) Heat 50 mL of distilled water in a beaker and raise the temperature of water by 15-20 ◦C (T2).
(Cool the thermometer tip with running tap water after the use)
4) Transfer quickly the hot 50 mL of water to the calorimeter having 50 mL of water and stir.
5) Note down the maximum temperature of water attained after mixing the hot water (T3).
Result: The heat capacity of the calorimeter is ___ J ◦C-1..