Question

Pantothenic acid is a B vitamin. Using the Dumaws method, you find that a sample weighing 71.6 mg gives 3.84 mL of nitrogen gas at 23°C.

a) Apply the Dumaws method
b) Identify the B vitamin
c) Calculate the molar mass
d) Determine the boiling point

Answer 1

b) Identify the B vitamin.To solve these questions, one would normally apply the Dumas method, calculate the number of moles with the ideal gas law, and infer the molar mass and identify the vitamin as B5.

Step-by-step explanation:

The student's question involves applying the Dumas method to a substance to determine its molar mass and identify the B vitamin, which in this case, is pantothenic acid. While the student's question does not provide complete details for the proper application of the Dumaws method (possibly a typo for Dumas), which involves heating a sample to produce a gas, measuring the gas's volume, and using that volume to calculate the molar mass, I'll guide you through a general approach to the problem:

• Using the measured volume of nitrogen gas, temperature, and given atmospheric pressure, calculate the number of moles of gas using the ideal gas law.
• Relate the number of moles of gas to the mass of the pantothenic acid sample to find the molar mass of the vitamin.

As for identifying the B vitamin, since pantothenic acid is known as vitamin B5, we can align with this identification. However, without additional data, such as the pressure during the measurement or the exact reaction used in the Dumas method, it is not possible to calculate the molar mass and boiling point.