Enthalpy Change of a Displacement Reaction

Authors Avatar

Chemistry Investigation——Enthalpy Change of a Displacement Reaction

Data Collection

  1. Table(1):Uncertainties
  1. Table(2)Quantitative observations of cold water and warm water

Table(3)Temperature changes when warm water was added into cold water

Table(4)Temperature changes when Zn(5g±0.1g) was added into 100mL±1mL CuSO4(0.500M)

  1. Table(5)Qualitative Observations

Data processing and presentation

This experiment includes two parts, the determination of a calorimeter constant and then the enthalpy change of the reaction between Zn and CuSO4.

Part A

  1. The heat absorbed by the cold water.

a) The mass of cold water.

m(water)=ρ(water)×V(water)

=1g/mL×50mL

=50g

Absolute uncertainty=±1mL

(Assume that the absolute uncertainty of ρ(water) is negligible)

% uncertainty=1/50 × 100%=2%

b) The change of the temperature

T is the temperature change after the warm water was added into the cold water.

T=38.2℃-20.2℃

=18

Absolute uncertainty= ±0.5℃ + ±0.5℃=±1℃

% uncertainty=1℃/18× 100%=6%

c) The heat absorbed by the cold water  

Q(cold water)=m×s×△T

=50g×4.18J/g℃×18

=3.8×103J

=3.8kJ

% uncertainty=2% + 6%=8%

(Assume that the absolute uncertainty of the specific heat of water is negligible)

Join now!

Absolute uncertainty=3.8kJ × 8%=±0.3kJ

  1. The heat released by the warm water.

a) The mass of warm water.

m(water)=ρ(water)×V(water)

=1g/mL×50mL

=50g

Absolute uncertainty=±1mL

(Assume that the absolute uncertainty of ρ(water) is negligible)

% uncertainty=1/50 × 100%=2%

b) The change of the temperature

T is the temperature change after the warm water was added into the cold water.

T=61.8℃-38.2℃

=23.6

Absolute uncertainty=±0.5℃ + ±0.5℃=±1℃

% uncertainty=1℃/23.6× 100%=4%

c) The heat released by the warm water  

Q(warm water)=m×s×△T

=50g×4.18J/g℃×23.6

=4.9×103J

=4.9kJ

% uncertainty=2% + 4%=6%

(Assume that the absolute uncertainty of the specific heat of water is negligible)

Absolute uncertainty=4.9 × ...

This is a preview of the whole essay