# 6.03 honors

Pages: 4 (756 words) Published: April 5, 2014
﻿Part I: The Dissolving of Solid Sodium Hydroxide in Water

Procedure
1. Measure out approximately 205 mL of distilled water and pour it into the calorimeter. Stir carefully with a thermometer until a constant temperature is reached. Record the volume of water and the constant initial temperature of the water on your data table. 2. Place a plastic measuring trough on top of the digital balance, and then zero the balance (press the tare button) so that the mass of the trough will be "ignored" and will not be added to the total mass measured by the balance. 3. Measure out approximately three to five scoops of solid sodium hydroxide and record the mass to your data table. 4. Place the solid sodium hydroxide into the water in the calorimeter and replace the lid immediately. Stir gently until the solid is completely dissolved and record the highest temperature reached.

Data and Observations
Distilled Water Volume
205.2 mL
Constant Initial Temperature
24.2°C
NaOH Mass
2.535g
Final Temperature
27.8°C

Calculations
1. Write out a balanced "equation" for the process you investigated in Part I, including phase symbols.

NaOH(s) + H2O(l) -> Na+(aq) + OH-(aq)

2. Calculate the number of moles of sodium hydroxide dissolved. Show your work.

3. Calculate the amount of energy involved in this dissolving process. Show your work.

qsurroundings = -qsystem
qsystem = -3.126kJ

4. Determine the enthalpy change, per mole of sodium hydroxide dissolved. Show your work.

Part II: The Reaction of Sodium Hydroxide Solution with Hydrochloric Acid

Procedure
1. Measure out approximately 100 mL of 0.50 M hydrochloric acid solution and 100 mL of 0.50 M sodium hydroxide solution. Record both volumes on your data table. 2. Pour the hydrochloric acid solution into the calorimeter. Measure and record the initial temperature of each solution and record on your data table. 3. Add the sodium hydroxide solution to the acid solution in the calorimeter...