A melting point of an old sample of Naphthalene was completed and a melting range of 78-79 °C was observed and recorded. The accepted literature value for the melting point of Naphthalene is 80.2 °C. A melting point of a sample of Urea was completed and a melting range of 120-129 °C was observed and recorded. The accepted literature value for the melting point of Urea is 133-135 °C. What does the melting point range and percent error suggest about the samples for Naphthalene and Urea ? 12pt Paragraph BIUAT²

Consider the following data that was collected for a protein that contain 0.76 % tryptophan amino acids by weight (Molecular weight of tryptophan amino acids is 204 g/mol). Absorbance Concentration (mg/L) 0.0250 0.100 0.150 0.226 0.259 0.400 0.600 0.964 1.14 1.78 1.45 2.35 1.78 2.87 How many mg of the protein present in 1.00 L solution that shows an absorbance of 1.20?

a) Lysine is an essential amino acid. It is taken by some people as a nutritional supplement in the form of a hydrated crystalline solid with the formula C6H₁4N2O2.XH₂O . To control the dose of lysine, it is essential to know the complete formula of the hydrate, which means determining the value of x. To determine the value of x in lysine hydrate, a pharmacist used a direct titration method. She dissolved 6.258g of the compound in approximately 100mL of distilled water and then made this up to 250mL in a volumetric flask. She then titrated 25mL aliquots of this solution with a standardized NaOH solution of concentration 0.1050 mol dm-³, obtaining a mean titre of 36.30 mL. In titrations, lysine behaves as a monoprotic acid. Use these data to determine the value of x in lysine hydrate. b) In a second experiment to verify the value of x, the pharmacist heated a 3.752g sample of the lysine hydrate to drive off all the water. When she reweighed the sample, the mass was 3.278 g. Use this…

Complete the separation scheme for the distillation experiment

What is the observable result in the test for glycerol? Give the equation involved in the test for glycerol.

Determine the compound (name or structure) from the data. Explain features from each data. Molecular formula: C3H8O

interpret/identify the peaks and its characteristics (C=O, 4H, etc.)

In a 0.73 mM aqueous solution of trimethylacetic acid (C₂H₂CO₂H), what is the percentage of trimethylacetic acid that is dissociated? You can find some data that is useful for solving this problem in the ALEKS Data resource. Round your answer to 2 significant digits. 1% 00 x10 X $

Three samples labelled A,B, and C possess identical melting points: 99 degrees. When a 75/25 mixture of A and B is prepared, it’s melting point is 90-95 degrees. The melting point of a 50/50 mixture of A and C is 79-91 degrees. The melting point of a 25/75 mixture of B and C is 97-98 degrees. What information does this tell you about the identity of the 3 compounds? What would you expect an an approximate melting range for a 75/25 mixture of B and C?

Which of the following is NOT characteristic of a quality restorative wax? a. The ability to acccept surface application of cosmetics b. Loss of shape and form under varying temperature c. The ability to adhere to tissue surfaces, even when tapered to a fine or thin edge d. The same light refractive characteristics as skin