Analysis
In cond conduc ucti ting ng the the expe experi rime ment nt,, the the sour source ces s of the the erro errors rs foun found d were were gene genera rally lly environmental, human and mechanical errors. For instance, the calorimeter was not a perfectly insulated, thereby, resulting to heat losses to the surroundings and affecting the temperature of the mixture. That is, when placing the water inside of it, either, it was not properly closed or there are water that needed to be wiped off from the metal’s surface. Regarding this, the experiment was held in an air-conditioned room which cools the obect faster than the normal temperature needed. To be particular in the first part, the time of immersion of the sample metals in boiling water was not obtained properly for the temperature. !oreover, the advantage of the stirrer for shortening the time to reach the e"uilibrium of the mixed sample was not used. This resulted to prolonging the room temperature affect the calorimeter. #ased on the gathered results, the computed values for the specific heat of aluminum and brass are the following$ %Table %Ta ble &' (art &$ )etermining the *pecific +eat of !etals Tria Triall &$ lumi luminu num m !eta !etall
Tria Triall $ #ras #rass s !eta !etall
Initial Temperature of metal, tom
℃
/ ℃
Final Temperature of mixture, tmix
01 ℃
2./ ℃
3xperimental *pecific +eat of !etal, cm
1.&424 cal5g-℃
1.162 cal5g-℃
1.&26 cal5g-℃
1.1&2 cal5g-℃
.7720 8
0.7/6 8
ctual *pecific *pecific +eat of !etal, !etal, cm (ercentage of 3rror
Graph 1. Temperature vs Specifc Heat o !umi"um 20 15
Specifc Heat #ca!%&'℃$ 10 5 0 8990919293949596
Temperature #℃$
The table shown above %Table &', displays the comparison between the experimental and actual value of the metal samples. The amount of heat capacity the aluminum was 1.&424 cal5g-9: which tells that the experimental value is far from having 1.&26 cal5g-9: of specific heat. This indicates that the increase specific capacity is not that credible to absorb heat before its temperature rises. ;n the other hand, the brass obtained 1.162 cal5g-9: heat capacity which is nearly close to the actual value. This tells that decreasing value of specific heat of brass has the ability to transfer heat to a cooler obect more readily. Furthermore, if the aluminum’s initial temperature is to be lowered, ranging from 1-/ it would give more less percentage of error %*ee
internal energy might lead to solidifying or free=ing. Furthermore, the ice from the second trial absorbed the heat better than the first one. The mass of the second trial has bigger value which resulted to a decrease in latent heat. This indicates that the proportionality of mass is inversely to the latent heat. The extracted amount of energy from the water to melting the ice can be computed by using the formula below$
Lf =
− M w C w ( t mix−t w ) + M c C c ( t mix −t c ) − M i C i ( t mix −0 ) M i
−( 241.6 ) ( 15 Lf = Lf =76.5967
Conclusion
The specific heat of the metal samples is determined by obtaining the masses of metal, calorimeter and water. !oreover, the difference of the final temperature of mixture %tmix' and initial temperature of metal must be computed.
C m =
and
the
calorimeter,
these
variables
can
be
expressed
as
−[( M w C w )( t mix −t m ) + M c C c ( t mix −t m ) ] .
M m ( t mix −t m )
luminum holds a 1.&/2 cal5g-9: as great as that of brass. This tells that it is 1.&/2 cal5g-9: as much heat to raise the temperature of aluminum than brass. !oreover, its greater specific heat value, enables the aluminum to absorb more heat before its temperature rises. The motion of atoms in the brass is fewer, since less heat is re"uired to ma>e the >inetic energy increase and raise it by &9:. The latent heat of fusion is ac"uired by having the masses of ice, water, and calorimeter. Furthermore, when finding the change in temperature, it is computed by having the difference of the final temperature of mixture and initial temperature of ice, %tmix ? toi'. s well as, the differences of the tmix and initial temperature of water, %tmixtw', and tmix and initial temperature of calorimeter. #y putting these altogether, the
variables can be expressed as
Lf =
− M w C w ( t mix−t w ) + M c C c ( t mix −t c ) − M i C i ( t mix −0 )
, given the values
M i
of specific heat capacity of ice, water, and calorimeter. The dependence of the mass of the ice greatly affects the outcome of the latent heat. For the reason that, that its proportionality is inverse to the latent heat. In converting the ice to li"uid, there should be an increase of internal energy. ;n the other hand, reducing it the internal energy might lead to free=ing and solidifying. To put this briefly, when a substance has a higher specific heat, it absorbs more heat before the temperature rises. nd as the specific heat value decreases, it has the potential to increase the transfer of heat to a cooler obect.
