Initial temperature in the calorimeter

1. Record the following:

a
Initial temperature in the calorimeter (C): 
b
Maximum temperature in the calorimeter from the reaction (C): 

c
Calculate deltaT by subtracting (b) from (c)
deltaT = Tinitial (C):




2. What was the initial heat energy before mixing the cold and hot water? To calculate this you need to use the formula :
Qinitial = m1*Cp*T(of the hot water) + m2*Cp*T(of the cold water)
where Q is the heat energy, m is the mass , Cp is the specific heat of water 4.184 J/g*C, and T is the temperature.




3. 3. What was the final heat energy after mixing the cold and hot water? To calculate this you need to use the formula :
Qfinal = (m1+m2) * Cp * Tfinal




4. What is the heat energy of the calorimeter? You can calculate the calorimeter heat energy as the difference between the initial and final heat energies. Choose the closest answer.





5. 5. What is the calorimeter constant? You can calculate the calorimeter constant, Ccal, per degree change of the calorimeter by taking the calorimeter heat energy and dividing it by the temperature change undergone by the calorimeter:





Experiment 2

1. Record the following for each of the three trials:

Trial 1
a
Mass of the empty calorimeter (g): 

b
Initial temperature in the calorimeter (C): 

c
Maximum temperature in the calorimeter from the reaction (C): 

d
Calculate deltaT by subtracting (b) from (c)
deltaT = Tmaximum - Tinitial (C):

e
Mass of the calorimeter and its contents after the reaction (g): 

f
Calculate the mass of the contents of the calorimeter (g): e - a
g
Calculate the moles of Mg reacted (MW=24.305 g/mole): 


Trial 2 
a
Mass of the empty calorimeter (g): 

b
Initial temperature in the calorimeter (C): 

c
Maximum temperature in the calorimeter from the reaction (C): 

d
Calculate deltaT by subtracting (b) from (c)
deltaT = Tmaximum - Tinitial (C):

e
Mass of the calorimeter and its contents after the reaction (g): 

f
Calculate the mass of the contents of the calorimeter (g): e - a
g
Calculate the moles of Mg reacted (MW=24.305 g/mole): 


Trial 3 
a
Mass of the empty calorimeter (g): 

b
Initial temperature in the calorimeter (C): 

c
Maximum temperature in the calorimeter from the reaction (C): 

d
Calculate deltaT by subtracting (b) from (c)
deltaT = Tmaximum - Tinitial (C):

e
Mass of the calorimeter and its contents after the reaction (g): 

f
Calculate the mass of the contents of the calorimeter (g): e - a
g
Calculate the moles of Mg reacted (MW=24.305 g/mole): 

2. Calculate the heat released into the solution for the 3 reactions, according to:

ﾠ ﾠ ﾠ q(reaction) ﾠ = ﾠ Ccal * Delta T + mass(contents) * Cp (contents) * deltaT
Cp is the specific heat (assume 4.18 J/goC)


a
Trial 1 (J)

b
Trial 2 (J)
c
Trial 3 (J)



3. Find the molar heat of reaction for each experiment in units of KiloJoules / (mole of Mg) by dividing the heat of reaction (converted to KJ by dividing by 1000) by the moles of Mg used.



a
Trial 1 KJ/mol
b
Trial 2 KJ/mol
c
Trial 3 KJ/mol


4. Calculate and record the average molar heat of reaction from the three results.

Attachment Preview: