Question

How would I calculate the heat of the reaction, number of moles, and enthalpy of the reaction from the information given?

Part 2. Enthalpy of neutralization. Carefully measure 50. mL of 2.0 M NaOH and add it to the calorimeter. Measure out 50. mL of 2.0 M HCl and place it in a dry beaker. Allow it to stand near the calorimeter for 3 or 4 minutes. Measure the temperature of the acid; rinse the temperature probe with tap water and wipe it dry. Insert the probe into the calorimeter and measure the temperature of the NaOH solution. The temperature of the acid and base should not differ by more than 0.5°C. If the temperature difference is greater, adjust the temperature of the HCl solution by either warming it gently with the palm of your hand or carefully running tap water of the outside of the beaker to cool the solution down. Record the temperature of the NaOH solution in the space marked 0.0 s. This serves as the initial temperature, Ti. As you tap the green start button, carefully add the 2.0 M HCl solution to the calorimeter all at once. Gently swirl the calorimeter solution throughout the data collection. Use the temperature probe and the Vernier LabQuest with the same sample collection rate as you did in Part 1 (i.e., record the temperature at 1 s intervals for the next ten minutes). You should also manually record your data at 30 seconds intervals on the report sheet as a backup. Be sure to export your data to your flash drive. Import the data to Excel and construct a temperature vs. time curve as shown in Figure 3 and determine AT (Tris obtained by extrapolating the linear portion of the curve to time zero). Calculate the heat transferred, Arxn, when the acid and base solutions were mixed. Note that the aqueous solution is absorbing the heat of the reactionthat is, heat is released, so the sign of the result is changed. Assume that the final volume of the reaction mixture is 100. mL and its density is 1.04 g/mL. Use a specific heat of 3.90 J gl °C for the resulting solution and calculate the heat 68

Answer 1

Reaction: NaOH HC NaCl H2O + Heat Data: V 50 mL, M= 2.0 M HCI (aq) NaOH V 50 mL, M = 2.0 M (aq) AT 10.5° C SH 3.90 J/g °C ? Яркn дн,? = 1.04 g/L Pmixture We calculate the moles of acid and base: moles of HCI = 2.00 mol/L x 0.05 L = 0.1 moles moles of NaOH = 2.00 mol/L x 0.05L = 0.1 moles Calculate total moles: total moles = 0.10 m ol es 0.1 moles 0.2 mol es n, Calculate total mass of mixture: —рх V mixture mixture = 1.04 g/mL x 100 mL m mixture = 104 g m mixture Calculate heat of neutralization: mmixture X SHmixture X (AL) 9rxn 104 g х 3.90 J/g °C х (10.5°C) Яm = -4258.8 J qcn=4258.8 J Heat released by the neutralization reaction Enthalpy of the reaction: Яркn дн, - nt 4258.8 J AHD 0.2moles AH, = -21294 J/mol