CHM130

Lab 4

Calorimetry

Name: Mengqi Li

Data Table: (12 points)

ALUMINUM METAL

Pre-weighed Aluminum metal sample mass (mmetal) 50.0 grams
Temperature of boiling water and metal sample in the pot (Ti(metal))

dsdfa(Ti 90.0 C
Temperature of cool water in the calorimeter prior to adding hot metal sample (Ti(water)) 17.0 C
Maximum Temperature of water/metal in calorimeter after mixing (Tf) 47.0 C

LEAD METAL

Pre-weighed Lead metal sample mass (mmetal) 50.0 grams
Temperature of boiling water and metal sample in the pot (Ti(metal)) 95.0 C
Temperature of cool water in the calorimeter prior to adding hot metal sample (Ti(water)) 17.0 C
Maximum Temperature of water/metal in calorimeter after mixing (Tf) 50.0 C

IRON …show more content…

(10 points)

Q=m(sh)ΔT=75*42.0*4.184=13000J

17. Use the equation: q = m(SH)ΔT to solve for the specific heat of the metal.
For q, you found how much heat was gained by the water so you know that same amount of heat was lost by the metal. Therefore, qmetal = -qwater. The mass of the sample was recorded from the baggie. The temperature change of the metal can be found in calculation #14. (10 points)

M(metal)*SH(metal)*ΔT(metal)=-m(water)*sh(water)*ΔT(water)
50.0*sh(metal)*(-40.0)=-75*4.184*42.0
Sh(metal)=6.59J/g0C

18. Determine the percent error using the equation and knowing that the actual specific heat of iron is 0.450 J/g(oC): (10 points)
Percent Error = actual-experimental x 100
Actua
=|0.450-6.59|/0.450*100
=1360%

Follow-Up Questions:
19. The First Law of Thermodynamics states that heat lost by one object is gained by another? For this lab experiment, what substance(s) gained energy and what substance(s) lost energy? (8 points)
Because one object lost heat and another will gain the heat. In this lab experiment, all metal lost energy, and all water gain energy.
20. To determine the specific heat of the metal, you assumed that the amount of heat lost by the metal equals the amount of heat gained by the water. Do you think this was a valid assumption to make based on your percent error? Discuss what may have occurred that would make your calculated value not equal to the actual value. (15 points)

Although some