Why heat of neutralisation from experiment is differ from theoretical value?

Answer 1

All resistors are manufactured with a built in tolerance level signified by the final colour band on it. These range from 0.01% to 20%. As the 20% one are much cheaper these are the ones that are more often used on not-critical applications and schools. This means that although they will normally be within 1%, a 1k resistor can be anywhere between 0.8k and 1.2k

Answer 2

There are several reasons experimental values differ from theoretical values. Most of them can be grouped into two categories - deficiencies in the model and deficiencies in the experiment.

1. The theory may not take into account all the variables that influence the actual value.
2. The operator may commit errors during the experiment such as incorrect weighing of the sample, measuring the wrong sample, improper preparation of the sample, etc.
3. Instruments used during the experiment may have faulty calibration
4. Samples being measured may be assumed to be pure but are in fact are contaminated.
5. Samples being measured may undergo a phase change or reaction during measurement (which the experimenter was not aware of)
6. The sample may not be in the phase you assume it is - different crystalline structures will have different heat capacities.
7. The density may not be what you assumed - this is particularly troublesome when you are near the critical point of a sample where small changes in temperature and especially pressure can have a drastic effect on the physical properties.
8. Faulty insulation may cause heat leakage into or out of the volume being measured (which were not accounted for)
9. If the measurement is supposed to be steady-state, if the value is taken before steady state is achieved, the experimental value will most likely be wrong.
10. If the measurement is dynamic, the rate of change may be too rapid, leading to a lag between energy input and temperature response - in essence, the thermal conductivity was not accounted for. This can be a particular problem when the sample is porous or a powder or granular - or when it has very low thermal conductivity.

To get the best results you need to thoroughly understand all factors that influence heat capacity, how the method of measuring works, and be very meticulous in conducting the experiment.

Answer 3

Because the reaction between a strong acid and a strong base usually releases -57kJ/mol of heat energy.That is the theoratical value. The heat energy released differs from the theoratical value as there might be some heat lost to the surroundings or there might be some heat energy that is absorbed by the container containing the acid or the base. Hope this helps!

Answer 4

We are not told what the theoretical value is, nor what the experimental results are, nor what the significance of the mention of equivalent resistance is, so nobody can satisfactorily answer this question.

Answer 5

Actual value is the measurement you get. Theoretical is the one that you obtain when trying to get percent yield of that substance.

Answer 6

In determination of volage by experiment there occur losses, whereas its not considered in theoritical calculation.

Answer 7

experimental percent error