Calorimetry

A. Determining the Heat Capacity of the Improvised Calorimeter

qsystem = qcal + qhot + qcold

To get accurate measurement of the heat of reaction, q, adiabatic condition should be provided.

In adiabatic condition, q = 0. Since qsystem = 0

qcal = - ( qhot + qcold)

qhot = mc(Tf – Th)

qcold = mc(Tf – Tc)

Supposed you gather the following data, calculate the heat capacity of the calorimeter, Ccal

(0C)

Temp of cold water (Tc) 35

Temp of hot water (Th) 80

Final temp of calorimeter (Tf) 52

Heat capacity of calorimeter , C

Before computing the heat capacity of the calorimeter, you need to calculate the heat of the calorimeter, qcal, first:

qcal = - ( qhot + qcold)

Since you used 25 mL of water and the density of water is 1.00g/mL, then the mass of the cold water and hot water is 25g, respectively.

qcal = - [(25g)(4.18J/g0C)(52 – 800C) + (25g)(4.18J/g0C)(52 – 350C)]

Give the value of qcal __________________________

Let’s define qcal

qcal = CT = C(Tf - Tc).

Since you already computed the qcal, you can solve now the Ccal, using this equation,

Ccal = qcal/(Tf - Tc)

Give the value of Ccal __________________________

B. Determining the Heat of Reaction between NaOH and HCl solution

qsystem = qcal + qwater+ qrxn

To get accurate measurement of the heat of reaction, q, adiabatic condition should be provided.

In adiabatic condition, q = 0. Since qsystem = 0

qrxn = - ( qcal + qwater) (qwater is also included in the equation since water is a solvent used for NaOH and HCl where heat exchange took place)

qcal here is actually obtained from the computation in part A and can be substituted readily.

Let’s define qwater,

qwater = ms(Tf-Ti)

Based on the experiment, write the actual value of Tf and Ti in the provided table.

(0C)

Initial temp before mixing (Ti)

Final temp of mixture (Tf)

Heat of reaction, qrxn

Calculate the heat of reaction, qrxn ______________________

C. Determining the Heat of Solution of MgSO4 and NH4NO3

qsystem = qcal + qwater+ qsoln

To get accurate measurement of the heat of solution, q, adiabatic condition should be provided.

In adiabatic condition, q = 0. Since qsystem = 0

qsoln = - ( qcal + qwater) (qwater is also included in the equation since water is a solvent used for MgSO4

and NH4NO3, respectively where heat exchange took place)

qcal here is actually obtained from the computation in part A and can be substituted readily.

Let’s define qwater,

qwater = ms(Tf-Ti)

Since 50 mL of water is used to dissolve 1g of MgSO4 and 1g of NH4NO3, respectively,

mass of water is 50g

Based on the experiment, write the actual value of Tf and Ti in the provided table.

MgSO4 NH4NO3

Initial temp before mixing (Ti)

Final temp of mixture (Tf)

Heat of solution, qsoln

Calculate the heat of solution, qsoln.

Heat of Solution of MgSO4 __________________

Heat of Solution of NH4NO3 __________________