Specific Heat

Purpose:
The purpose of this activity is to determine the specific heat of a metal object and identity the
metal based on its specific heat.

Background:

                          Specific Heats                    J/g*c
                               Water                            4.184
                                   Al                              0.897
                                 Brass                           0.385
                                  Cu                              0.385
                                 Lead                            0.129
                          Stainless Steel                    0.490
                                   Zn                              0.390

In the specific heat lab, you learn how to measure the amount of calories of an unknown metal that were released as the metal is heated in a beaker of water. In order to do this lab, you need to collect the temperatures and masses.

Equation for Specific Heat: Qw = mw*cw*∆Tw
Q is the heat gained. m is the mass. c is the specific heat. ∆T is the change in temperature. For this experiment, we need to plug in the data for both the water and the metal for each trial.

Data:

Trial 1:
Temperature of water:                                                   20.3 C
Temperature of water and metal                                   20.5 C
Temperature of water and metal (boiled)                      99.3 C
Temperature of the metal in Styrofoam                        26.0 C
Temperature of the cold water                                      21.0 C

Mass of beaker                                                             116.84g
Mass of beaker and water                                             257.73g
Mass of beaker, water and metal                                  285.71g
Mass of beaker, water and metal (boiling)                   271.89g
Mass of the Styrofoam                                                 2.00g
Mass of Styrofoam and water                                      96.55g

Trial 2:
Temperature of water:                                                  20.1 C
Temperature of water and metal                                  20.3 C
Temperature of water and metal (boiled)                    99.5 C
Temperature of the metal in Styrofoam                       20.0 C
Temperature of the cold water                                     26.3 C

Mass of beaker                                                            116.85g
Mass of beaker and water                                           231.98g
Mass of beaker, water and metal                                278.10g
Mass of beaker, water and metal (boiling)                 265.50g 
Mass of the Styrofoam                                               2.00g
Mass of Styrofoam and water                                    96.55g

Calculations: Qw = mw*cw*∆Tw

Temperature Water changed:
99.3 C - 21.0 C = 78.3 C

Heat water gained:                         
Q = 94.55 g x 4.184 J/g*C X 78.3 C = 30,975.26                            

                   
specific heat: for metal
   Q      =  c
  m*c           

1974.848 J            = .897 J/g*c
2022.954 g*c

Analysis:
I learned you can never be too careful when taking measurements. Also, I learned it is best to have a good plan of what will need to be measured, how it will be measured, and the most efficient way to measure it.

Conclusion:
The metal we received was Aluminum because the specific heat matched up perfectly: 0.897.