An Investigation Of Hess' Law

Aim: To verify Hess rectitude
Research Question: How can Hess right be use to find the enthalpy of solution of atomic number 11 hydroxide using the neutralization chemical response between atomic number 11 hydroxide and hydrochloric acid.
Theory: Following the law of conservation of energy, Hesss Law states that the total enthalpy change for a reaction is equal to the energy lost or gained by the system. This law remains true no matter what the reaction or the steps and ways in which a particular reaction occurs. Theoretically, energy is never lost from a system. It is simply converted to another set of products.
In this experiment,
NaOH(s) + HCl(aq) NaCl(aq) + H2O(l) [H1]
NaOH(s) NaOH(aq) [H2]
NaOH(aq) + HCl(aq) NaCl(aq) + H2O [H3]
According to Hesss Law [H1] = [H2] + [H3]
Therefore [H2] = [H1] - [H3]
Variables:
Independent Variable: The state of NaOH used in the three experiments. These different states enable the data that provide be used to verify Hesss law to be collected.
Dependent Variable: The enthalpy changes of the three reactions that will diverge with different states of NaOH used.
Controlled Variables: The room temperature and pressure. The temperature of all the solutions used kept continual at room temperature.
Apparatus:
* 50 cm3 measuring cylinder (± 0.



5 cm3)
* Polystyrene cup with lid
* Cotton
* Thermometer (± 0.5 °C)
* 100 cm3 of 1M HCl
* 50 cm3 of 1M NaOH
* 50 cm3 of distilled water
* 2 grams of unshakable NaOH
* Stopwatch
* Pan balance (± 0.001 g)

Procedure:
Measurement of [H1]
1. Measure 50 cm3 of HCl (1M) and pour it into the polystyrene cup.
2. Close the lid of the cup and insulate it with cotton.
3. take out approximately 2 grams of solid NaOH pellets.
4. Measure the temperature of the HCl and straggle the stopwatch.
5. Measure the temperature once more after 30 seconds.
6. afterwards the stopwatch has reached 60 seconds, quickly open the lid of the...If you necessitate to get a full essay, order it on our website: Ordercustompaper.com



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