# Enthalpy of Neutralisation Between HCl and NaOH

by lizzielunn817gmailcom (student)

Year 12 Chemistry
Enthalpy of Neutralisation
Internal Assessment

Raw Data Table:

Table displaying the relationship between temperature and time after 20cm3 of an HCl solution is combined with 20cm3 of a NaOH solution

Qualitative:

• The temperature probe often touched the bottom of the cup.
• Not all the liquid was poured out of the measuring cylinder
• The measuring cylinder had to been rinsed before each measurement meaning it may have been contaminated.
• The two reactants are both clear liquids and when mixed, the result is also a clear liquid. There is no colour change seen in the experiment
• The container of the neutralizing NaOH and HCl rose slightly in temperature, and at the end of the experiment felt slightly warmer than before the experiment
• When stirring, the stirring rod sometimes knocked against the temperature probe
• Small bubbles could be seen to form, most likely as a result from passionate stirring.

Graph Title

Calculations

By looking at my table I can see that the max temp is __
If we then subtract the initial average temperature from this value thus:

°C         (T = ± 0.05)

(

= ± 0.1)

(

= (± 0.1/6.2 °C)

100 = ±1.61%)

Therefore, the average change in temperature for this experiment is calculated to be ΔT= 6.2°C

Using the equation

, we can ascertain the amount of energy, in joules, lost by the NaOH and HCl solutions when they neutralized to form H2O and NaCl:

For m we are using the value of 40 grams for 20cm3 of HCl and 20cm3 of NaOH, and C is a constant at ~4.18Jcm-3°C-1 (3 s.f). Therefore,

( %m = (1/40)

100 =±2.5% )

Joules                                                (

...