| Aim | (a): Enthalpy of dissolution of Copper Sulphate or Potassium Nitrate. (b): Enthalpy of neutralization of strong acid (HCI) and strong base (NaOH). (c): Determination of enthalpy change during interaction (Hydrogen bond formation) between Acetone and Chloroform. |
| Apparatus Required | For experiment (a) Copper Sulphate or Potassium Nitrate Distilled water Styrofoam cup Thermometer Stirrer For experiment (b) Hydrochloric acid Sodium hydroxide Distilled water Styrofoam cup Thermometer Stirrer For experiment (c) Acetone Chloroform Distilled water Styrofoam cup Thermometer Stirrer |
| Theory | Enthalpy of dissolution is the amount of heat absorbed or released when a solute dissolves in a solvent. It can be calculated by measuring the temperature change that occurs during the dissolution process. Enthalpy of neutralization is the amount of heat released when an acid reacts with a base to form a salt and water. It can be calculated by measuring the temperature change that occurs during the neutralization process. Hydrogen bonding occurs when a hydrogen atom bonded to an electronegative atom (such as nitrogen, oxygen, or fluorine) interacts with another electronegative atom. The enthalpy change of hydrogen bonding can be determined by measuring the temperature change that occurs during the interaction between two substances |
| Procedure | Procedure of experiment (a) Measure 50 mL of distilled water using a graduated cylinder and pour it into the Styrofoam cup. Record the initial temperature of the water using a thermometer. Add 1 gram of Copper Sulphate or Potassium Nitrate to the water. Stir the solution using a stirrer until the solid dissolves completely. Record the final temperature of the solution. Calculate the enthalpy change using the formula: ΔH = q/n where ΔH is the enthalpy change, q is the heat absorbed or released, and n is the number of moles of solute. Procedure of experiment (b) Measure 50 mL of distilled water using a graduated cylinder and pour it into the Styrofoam cup. Record the initial temperature of the water using a thermometer. Add 25 mL of hydrochloric acid to the water. Record the temperature of the solution. Add 25 mL of sodium hydroxide to the solution. Record the highest temperature reached by the solution. Calculate the enthalpy change using the formula: ΔH = q/n where ΔH is the enthalpy change, q is the heat absorbed or released, and n is the number of moles of acid or base. Procedure of experiment (c) Measure 50 mL of distilled water using a graduated cylinder and pour it into the Styrofoam cup. Record the initial temperature of the water using a thermometer. Add 10 mL of acetone to the water. Record the temperature of the solution. Add 10 mL of chloroform to the solution. Record the highest temperature reached by the solution. Calculate the enthalpy change using the formula: ΔH = q/n where ΔH is the enthalpy change, q is the heat absorbed or released, and n is the number of moles of acetone or chloroform. |
| Observation and Result | Observation: The temperature of the solution increases during the dissolution process. Result: The enthalpy of dissolution of Copper Sulphate or Potassium Nitrate can be calculated from the temperature change observed during the dissolution process. Observation: The temperature of the solution increases during the neutralization process. Result: The enthalpy of neutralization of hydrochloric acid and sodium hydroxide can be calculated from the temperature change observed during the neutralization process. Observation: The temperature of the solution increases during the interaction between acetone and chloroform. Result: The enthalpy change of hydrogen bonding between acetone and chloroform can be calculated from the temperature change observed during the interaction process. |