Melting Point Experiment Unknown C: Melting point of Unknown C: Candidate compounds from Table 1: 1. M.P. 2. M.P. 3. M.P. 4. M.P. Mixed melting point ranges with Unknown C: Unknown + 1: M.P. Unknown + 2: M.P. Unknown + 3: M.P. Unknown + 4: M.P. Identity of Unknown C: Complete the following exercises in the spaces provided: 1. Describe the effects of impurities on the melting point of a pure substance. 2. Based on your experience with this simulated experiment, what is a reasonable definition of a p substance. An unknown solid has a melting point of 132-135°C. A mixed melting point of the unknown v urea, gives a melting point of 120-126°C. Based on your understanding of the effects of impurities melting points, is the unknown urea or not? Briefly explain your answer. 3. a) An unknown solid has a melting point of 112-114°C. Based on data from Table 1 above and mixed melting point technique of this experiment, you can narrow down the possibilities to ti compounds. List the compounds. 4. b) A mixed melting point of the unknown with acetanilide gives a melting point of113-114 the unknown acetanilide or not? Briefly explain your answer.

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Preparation of 0.25N NaOH Objective: Apparatus and Materials: Procedure : Calculate the exact mass of NaOH needed to prepare 1.0L of 0.25N NaOH for standardization. Show your computations. Using the triple beam balance, weigh the desired amount of NaOH. Place the weighed amount of NaOH into the 500 mL volumetric flask and add distilled water until it reaches the mark. Agitate and transfer the solution into the reagent bottle. Add again distilled water to the same volumetric flask until it reaches the mark and pour it to the same reagent bottle, thus having a total volume of 1.0 L. Label the reagent bottle, 0.25N NaOH.   Data and Computations:       Conclusion: