Fildia Putri, Rafika Sri Rahayu,Nul Lailah , NurulWisnaAfianti, NurRahmah
Department Of Chemistry ICP FMIPA UNM 2013
Have done the experiment titled "Joule Experiment" aimed to determine the heat of
reaction or heat of dissolution with the calorimeter. Thermochemical study of heat is generated or
required by a chemical reaction. The principle of the experiment is the Principle of Black, Black is
a legal principle that the study of heat change of the system to the environment and vice versa.
Equal to the heat given off heat absorbed (Q accept = Qloose). The method used in this experiment is a
method of calorimetryby using a tool called a calorimeter. In this experiment the electrical energy
released will be accepted by the water and calorimeter. Heat equal to the heat released is accepted,
then the electrical energy that is released will be accepted by the water in the calorimeter and the
calorimeter itself, so there will be changes in the water and calorimeter heat. On joule experiments
were based on the theory of the calorific value of equivalence of electricity at 4,186 Joules /
calorie values of equality, while the heat energy and mechanical energy based on our calculation
of 4,72 Joule / calorie. This difference is caused by the system and the environment while doing
Thermodynamics target is to get the energy relations of against the other.
With the conservation of energy, so if a kind of energy shrinkage, other energy
kinds will be generate for example, energy electricity produced by a generator
does not just happen, but the generator is driven by the potential energy and
depreciation kinetic energy of water. Electrical energy generated by the generator
plus the energy lost due to friction force should be equal to the energy
mechanically given by the turbine. The first law of thermodynamics is a general
statement the process of change is one form of energy into a form of energy other.
Presumably it is always possible to make heat energy equivalent to another
energy. If a certain mass of the falling weight of a height, the potential and kinetic
energy lost will change equivalent to thermal energy. This event would not have
happened otherwise so alone, but must wear specific tools to elevate the fallen
mass. Not possible mass falling energy is directly equivalent to the potential
energy back position to the original.
Here is the first law never said direction of a process. To determine the
direction of the latter is to talk about the law, so that a combination of the first and
second laws can be used to predict where that process can occur
If there is an electric current in a conductor, then the tone aka electrical
energy is converted into heat energy. I definitely flow, energy conversion greater
resistance to arrest or larger conductors. This phenomenon has the same analogy
to the conversion of chemical energy into thermal energy due to friction
The resulting heat (electric deleted) in an electrical circuit called the Joule
heat (Joule heat), because they were discovered by the English physicist James
Prescott Joule (1818-1889). The experts examined the conversion of electrical
energy into heat energy (also mechanical energy into heat energy).
In some electrical applications, such as electric motors, heat joule is
something that is not desirable, but in other applications such as electric power
and heat grill, electrical energy is converted into heat intentionally. In this study,
the effect of heat on the electric current and the heat equivalent of the electricity
will be investigated
Key Words: Calorie, Joule, Energy, Calorimeter.
1. Understanding the principle of equality (equivalence) the heat energy and
Determining the value of equality mechanical energy and heat energy.
Heat transfer is energy in transit, and it can be used to do work. It can also
be converted to any other form of energy. A car engine, for example, burns fuel
for heat transfer into a gas. Work is done by the gas as it exerts a force through a
distance, converting its energy into a variety of other forms—into the car’s kinetic
or gravitational potential energy; into electrical energy to run the spark plugs,
radio, and lights; and back into stored energy in the car’s battery. But most of the
heat transfer produced from burning fuel in the engine does not do work on the
gas. Rather, the energy is released into the environment, implying that the engine
is quite inefficient.
It is often said that modern gasoline engines cannot be made to be
significantly more efficient. We hear the same about heat transfer to electrical
energy in large power stations, whether they are coal, oil, natural gas, or nuclear
powered. Why is that the case? Is the inefficiency caused by design problems that
could be solved with better engineering and superior materials? Is it part of some
money-making conspiracy by those who sell energy? Actually, the truth is more
interesting, and reveals much about the nature of heat transfer. Basic physical
laws govern how heat transfer for doing work takes place and place
insurmountable limits onto its efficiency. This chapter will explore these laws as
well as many applications and concepts associated with them.
If we are interested in how heat transfer is converted into doing work, then
the conservation of energy principle is important. The first law of
thermodynamics applies the conservation of energy principle to systems where
heat transfer and doing work are the methods of transferring energy into and out
of the system. The first law of thermodynamics states that the change in internal
energy of a system equals the net heat transfer into the system minus the net work
done by the system
The first law of thermodynamics:
The first law of thermodynamics is a statement of the law of conservation
of energy. This law describes the results of many experiments which connects
the work done on the system, heat is added or subtracted from the system, and
the system's internal energy. From the initial definition of calories, we know
that it takes 1 calorie of energy to raise the temperature of 1 gram of water to
1 0 C. But we also can raise the temperature of water or any other system to
do her business without adding a bit of heat from the outside.
Joule + Element
Picture 7.1. Devices Joule experiment
Image. 7.1 above shows the schematic diagram of the Joule
modification that can be used to determine the amount of effort equivalent to
a certain amount of heat, the amount of effort required to raise the
temperature of one gram of water by one degree Celsius.
The water in the calorimeter in Fig enclosed in walls insulation system
so that the temperature can’t be affected by the heat in or out of it. By giving
potential difference V S at the ends of the coil in the calorimeter, an electric
current will flow through the ammeter and the potential difference will occur
at the ends of the coil that will produce electricity businesses on the system to
heat the water. This effort is known as joule heating, which can be expressed
WhereV is the potential difference of the ends of the element, I is the electric
current in the circuit, and t is the time drainage flows into the system. Heat
energy given off by the electrical elements will be accepted by the water and
calorimeter system so that the temperature is increased (the exception phase
Q is the heat energy needed to raise the temperature of water is
proportional to the change in temperature T and mass m, namely:
Wherec is the specific heat of water.
Joule experimental results and subsequent experiments is that the
effort it takes 4.18 units of mechanical or electrical (joule) to raise the
temperature of 1 gram of water by 1 0 C, or 4.18 J of mechanical or electrical
energy is equivalent to 1 cal of heat energy.
Tools and Materials
Variable DC Power Supply,
Ammeters 0 - 5 A DC,
Voltmeter 0 - 50 V DC,
Joule Calorimeter complete,
311g Balance Sheet,
a. Control Variable
b. Manipulation Variable
: Mass of water and Calorimeter
c. Respond Variable
1. Manipulation Variable : Water Mass and Calorie Meter
The density is the mass per unit of volume measurement object. The
higher the density of an object, the greater the mass per volume.
2. Respond Variable : Time
Time is all of series when process, act, or state lasts. In this condition,
more high the water mass, the time for upper the 100c temperature is too
long. And the otherwise
3. Control Variable : Strains
Voltage is the different of electricity potential between two points in
electrical circuits, and stated in volt unit. This scale measure the potential
energy from electric field which involve the electricity from electrical
conductor. In this situation, more high the voltage, the electricity which
flow into calorie meter is higher. It’s such as time which need for increase
the temperature in the amount of 10º c is faster.
a. Assemble experimental scheme in Figure 7.1 above.
b. Do not turn on the power supply before you make sure that the
polarity and measuring limit of the source and flow measuring
instruments and correct voltage.
c. Measure the mass of the empty calorimeter + stirrer.
d. Fill the calorimeter with water and measure its mass by half.
e. Put on the full calorimeter circuit, then turn on the power supply
and set it to the current flowing at 2A, note the current and
potential difference across the ends of the coil.
f. Turn off the Power Supply back with no change in the position of
the voltage regulator.
g. Measure the temperature of the calorimeter and its contents and
record the initial temperature.
h. Turn on the Power Supply along with running a stop watch to
measure the time until the current drainage system temperature
rose to 10 0 C (in consultation with the Assistant Supervisor) of the
initial temperature and stop the stop watch simultaneously by
turning off Power Supply. Note the appointment of a stop watch.
i. Repeat this activity up to 3 (three) times.
RESULTS OF OBSERVATIONS AND DATA ANALYSIS
RESULTS OF OBSERVATIONS
Ohauss Balance NST = 311 g
= 0,2 V
Ampere meter NST
= 0,1 A
= 0,2 s
Table 1.Table of observation
The measurements Scale measurements
Mass of empty calorimeter +
stirrer, m1 (kg))
Mass of calorimeter + water, m2
Mass of water, ma (kg)
voltages, V (volt)
Electricity, I (A)
The first temperature, T0 (0C)
The last temperature, Tf (0C)
Time , t (s)
Calorimeter is a tool to determine the specific heat of thin copper included
in the larger vessel. On the reason given several pieces of cork wedge. In
principle, the small vessel (inner wall) with large vessel (outer wall) is limited by
the material that can’t be drained of heat (adiabatic). Then, given a cap that has
two holes to insert / place the thermometer and stirrer.
With the specific heat measurements are based on the principle of Black
Calorimeter, which is received by the Calorimeter heat equal to the heat supplied
by the heat of its kind sought substance. This implies that if two objects of
different temperatures come in contact with each other, it will be towards
At this time experiments related to two forms of energy, ie heat and
electricity waterwheel. Electrical energy produced by a power supply on a resistor
is expressed by the equation:
Where W = electrical energy (joules)
V = voltage (volts)
I = electric current (Volt)
t = time / long flow of electricity (second)
The amount of heat needed to raise the temperature of a substance is expressed by
Q = mc (T a - T)
Where Q = amount of heat required (calories)
m = mass of substance (g)
substance c = specific heat (cal / g 0 C)
T a = Final temperature of substances (0 C)
T = Initial temperature (0 C)
The working principle of the calorimeter is the flow of electric current in the
coil of wire conductor is inserted into distilled water. At the time of moving in a
wire conductor (due to potential difference) of the charge carriers collide with the
metal atoms and lose energy. As a result of the charge carriers collide with a
constant speed that is proportional to the electric field strength. Collisions by the
charge carriers will cause metal electrified the energy gain of heat energy / heat.
Based on the results of lab data is known that the greater the value of
voltage and electric current in a material so hot power possessed by the material
gets smaller. In the lab result data as shown that measurements using small
currents produce little value. This is an incorrect assumption because the
The first measurement of changes in temperature, which is very small in
contrast to data using large currents. But if the temperature changes as large as it
is fast, little has a great power.
Of experiments, observations and calculations have been carried out, it can be
concluded as follows.
1. Not all hot absorbed by water and calorimeter however also by wire spiral
in case this not be calculated as well as plastic black cover calorimeter.
2. On calorimeter there energy dissipation.
energy dissipation can mean energy
lost from one systems.
3. More and more increasingly large volt large energy generated electricity.
4. More and more the small volt small Q generated.
And From the above experiments it can be concluded that large - small mass of
water and the time used greatly affect the resulting temperature or in other words,
high and low temperature produced is strongly influenced by the mass amount of
water used and the length of time and the amount of voltage used. With a large
number of voltages and currents are still going strong rise in water temperature
every minute on the minute, although certain
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