Is There a Change in Temperature when an Alkali Neutralizes an Acid? Aim The aim of the experiment was to find out if there was a change in temperature when we added an alkali (Sodium Hydroxide) to an acid (Hydrochloric Acid) to neutralize it. Hypothesis We hypothesized that there was going be a raise in temperature as we add 1ml of Sodium Hydroxide at a time to the Hydrochloric Acid due to the neutralization of the acid. The neutralization is chemical reaction that causes an exothermic reaction. Sodium Hydroxide + Hydrochloric Acid Sodium Chloride + Water NaOH(aq) + HClaq → NaCl(aq) + H2O(l) Variables Independent The independent variable of the experiment was the amount of sodium hydroxide that we added to the acid.
After shaking the cup gently to ensure that the mixture reached the equilibrium temperature quickly, we measured the final temperature to get the ‘T2' value. We repeated these steps three times for each individual metal object. Results: Data Set 1 aluminum m(g) T1 (°C) Mw (g) Tw(°C) T2(°C) c(cal/g°C) 1 26.5 100 100 23.0 27 .207
Close the top 5. Put in Thermometer 6. Record starting temperature 7. Use the stirrer to help stir the water and mix it with the sodium chloride 8. Wait until the temperature stops increasing and record the final temperature Data: When the sodium chloride was added to the water, the water started to heat up.
Boil at least 10 minutes. 7. While the metal is still in the boiling water bath, measure the temperature of the boiling water carefully with a thermometer and record to tenths, one decimal place, in Data Table 2 8. After the metal has been heating 10 minutes, remove the metal from the boiling water bath using the string. Immediately transfer the metal into the calorimeter cup so that the water covers the metal.
3. Measure the temperature of the two solutions. Pour the contents of the second beaker into the first, immediately start the clock and shake to mix. 4. When the blue colour of the starch-iodine complex appears, stop the clock and write down the time in the Results Table.
The normality of the unknown base is calculated after the solution has reached the end point. The amount of substance being delivered is calculated in units of equivalents per litre using the formula: VaNa = VbNb Experimental In order to titrate the acid with the unknown base, a solution of the acid was prepared. 5.1722 (±10%)g of potassium hydrogen phthalate acid is obtained using a weighing boat and transferred into a volumetric flask containing 250mL of boiled distilled water. Volumetric flask was shaken several times in order to assist the powder to dissolve. Once dissolved, 24.9734 (± 0.0045)mL of acid was pipetted into an Erlenmeyer flask along with 25mL of cool (recently boiled) distilled water.
Record the initial temperature of the liquid in the calorimeter. Watch the thermometer until maximum temperature is achieved. Weigh out 2.0g of NaOH pellets. Record the temperature of the distilled water in the calorimeter until the temperature is constant then add all of the pellets at once. Gently stir the pellets until the acid is dissolved by shaking the the apparatus.
State Change Lab Report By: Swerve Lord Date: 10/26/11 Class Period: 2 State Change * Focus Question- * How does temperature change during the melting process from a solid to a liquid? * Word List- * Lauric Acid- * A fatty acid, CH3(CH2)10COOH, obtained through coconuts, and it is used for making soaps and cosmetics. * Melting- * The Phase Change from a solid to a liquid. * Heat- * The transfer of energy from one body to another as a result of a difference in temperature or a Phase Change. * Solid- * A form of matter that is of definite shape and volume.
* Document the time it takes .I will repeat the process three times and take the average amount of time it took for the solute to dissolve in the solvent of high temperature. * Secondly I will start the second experiment with moderate amount of temperature for example the temperature of the solvent could be half of the temperature of the previous experiment and follow the same steps. * Finally for my third experiment, I will use cold tap water and follow the above steps and compare my findings by filling the results in the table. I also make sure that equal amount of solute and solvent added in to the container to make my findings more accurate. The table below shows the result of the experiment Time taken for sugar to dissolve (sec) | Volume of water | Temperature of water | 1st result | 2nd result | 3rd result | Mean result
Objective To determine of heats from three exothermic reactions and investigate the Hess Law Summary Based on this experiment, we have study three related exothermic reactions involving sodium hydroxide. The first reaction (Part A), solid sodium hydroxide will dissociate into water. The heat produce by this reaction (∆H1) and this called as the heat of solution of solid NaOH. From the experiment we have managed to determined that ∆H1 = -41.84 KJ/mol In the second reaction (Part B), an aqueous solution of NaOH is allowed to react with an aqueous solution of HCl. This is a neutralization reaction between a strong acid and strong base.