Photo AI
You are to determine the enthalpy change for the reaction of hydrated sodium carbonate, Na2CO3.xH2O, with hydrochloric acid, HCl(aq) - CIE - A-Level Chemistry - Question 2 - 2011 - Paper 1
Question 2
You are to determine the enthalpy change for the reaction of hydrated sodium carbonate, Na2CO3.xH2O, with hydrochloric acid, HCl(aq). The equation for this reaction... show full transcript
Worked Solution & Example Answer:You are to determine the enthalpy change for the reaction of hydrated sodium carbonate, Na2CO3.xH2O, with hydrochloric acid, HCl(aq) - CIE - A-Level Chemistry - Question 2 - 2011 - Paper 1
Step 1
Method
Answer
-
Support the Plastic Cup: Place the plastic cup inside a 250 cm³ beaker to provide stability during the experiment.
-
Measure the Hydrochloric Acid: Use a measuring cylinder to accurately transfer 25 cm³ of hydrochloric acid (FB 4) into the plastic cup.
-
Tilt the Beaker: Carefully tilt the beaker so that the bulb of the thermometer is immersed in the solution to obtain a precise temperature reading.
-
Measure Initial Temperature: Measure and record the initial temperature of the hydrochloric acid solution before adding the sodium carbonate.
-
Weigh the Sodium Carbonate: Measure and record the mass of the tube containing the hydrated sodium carbonate (FB 3).
-
Add Sodium Carbonate: Carefully tip all the weighed hydrated sodium carbonate into the plastic cup containing hydrochloric acid. This will initiate the reaction.
-
Observe Effervescence: Be aware that effervescence will occur due to the release of gas (CO2). Add the sodium carbonate in small portions while constantly stirring with the thermometer to ensure thorough mixing.
-
Record Temperature after Reaction: After adding the sodium carbonate, record the highest temperature of the solution reached during the reaction.
-
Reweigh the Tube: After the reaction, reweigh the tube to determine any residual amount of sodium carbonate left unreacted (FB 3).
-
Document Data: In the provided space, record both balance readings, both temperature measurements, the mass of sodium carbonate used, and the decrease in temperature of the solution.