An example of a laboratory experiment report on determining an unknown substance with a melting point of 178°C.

Title: Determination of Unknown Substance with a Melting Point of 178°C

Objective:
The objective of this experiment is to determine the identity of an unknown substance with a melting point of 178°C.

Materials:
- Unknown substance
- Melting point apparatus
- Thermometer
- Watch glass
- Bunsen burner
- Test tubes
- Stirring rod

Procedure:
1. Set up the melting point apparatus according to the manufacturer's instructions.
2. Place a small amount of the unknown substance on a watch glass.
3. Insert the thermometer into the melting point apparatus and set the temperature range to 150-200°C.
4. Heat the unknown substance slowly using a Bunsen burner while stirring with a stirring rod.
5. Record the temperature at which the unknown substance begins to melt and the temperature at which it completely melts.
6. Repeat the experiment two more times to ensure accuracy.

Results:
The unknown substance had a melting point range of 176-180°C. The average melting point was calculated to be 178°C.

Discussion:
Based on the melting point of 178°C, the unknown substance is likely to be compound X. Compound X has a known melting point of 178°C, which matches the melting point obtained in this experiment. Therefore, it can be concluded that the unknown substance is compound X.

Conclusion:
The unknown substance with a melting point of 178°C was identified as compound X based on the melting point obtained in the experiment. The experiment was successful in determining the identity of the unknown substance.

Title: Determination of an Unknown Substance with a Melting Point of 178°C

Introduction:

The melting point of a substance is the temperature at which it changes from a solid to a liquid. This property can be used to identify unknown substances because it is a unique characteristic for each compound. In this experiment, we will determine the melting point of an unknown substance and use this information to identify it.

Materials:

- Unknown substance
- Melting point apparatus
- Thermometer
- Capillary tube
- Bunsen burner
- Matches

Procedure:

1. Fill the melting point apparatus with a layer of oil.
2. Insert a capillary tube into the apparatus and attach it to the thermometer.
3. Place a small amount of the unknown substance into the capillary tube.
4. Heat the oil bath slowly using a Bunsen burner.
5. Observe the substance through a magnifying glass as the temperature rises.
6. Record the temperature at which the substance starts to melt.
7. Continue heating until the substance is completely melted.
8. Record the temperature at which the liquid solidifies.

Results:

- Melting point onset: 176°C
- Melting point range: 176-178°C
- Solidification point: 178°C

Discussion:

The melting point of the unknown substance was determined to be 178°C. This value can be used to identify the substance by comparing it to known melting points of known compounds. According to a database of melting points, the substance with a melting point of 178°C is aspirin.

Conclusion:

The melting point of the unknown substance was determined to be 178°C, which corresponds to the melting point of aspirin. Therefore, the unknown substance is identified as aspirin.