The Dumas method of molecular weight determination was historically a procedure used to determine the molecular weight of an unknown substance. The Dumas method is appropriate to determine the molecular weights of volatile organic substances that are liquids at room temperature..
Moreover, how does the Dumas method work?
The Dumas method is one of the simplest ways to measure the molecular weight of a substance. It uses the ideal gas law. In this method we have to confine a sample of gas in a container of known volume, making sure when we do this that the sample is exactly at atmospheric pressure.
Furthermore, why is it important to not allow water into the Dumas bulb? It is extremely important that no water gets inside the flask and that the water in the bath is already boiling when you immerse the flask. Mount the thermometer in the bath, so it is as close to the unknown as possible. The unknown is a volatile liquid that boils at a temperature below that of water.
Similarly, you may ask, what is Dumas reaction?
This reaction is called the “Dumas reaction” in honor of the French chemist Jean-Baptiste Andre Dumas, and is a decarboxylation reaction, i.e. carbon dioxide separates from the carbonic acid molecule.
How do you estimate nitrogen by Dumas method?
Dumas method - Estimation of nitrogen. This method is based upon the fact that nitrogenous compound when heated with cupric oxide in an atmosphere of CO2 yields free nitrogen. Traces of oxide of nitrogen, which may be formed in some cases, are reduced to elemental nitrogen by passing over heated copper spiral.
Related Question Answers
Why was the unknown liquid vaporized in a boiling water bath?
Why was the unknown liquid vaporized in a boiling water bath, rather than at room temperature? Because the boiling point of the unknown is higher than room temperature, so it requires a boiling water bath to allow it to vaporize. volume of 0.05 mL and water has a density of 1.0 g/mL.What happens to the volatile liquid that is placed in the flask?
A small amount of the liquid is introduced into a weighed flask. The flask is then placed in boiling water, where the liquid will vaporize completely, driving out the air and filling the flask with vapor at atmospheric pressure and the temperature of the boiling water.What are volatile liquids?
Liquid that evaporates at room temperature, or vaporizes easily. Volatile liquids have low boiling point. Volatile just means "easily evaporates.". In other words, the higher is the vapor pressure of a liquid, the higher is the volatility and the lower is the normal boiling point of the liquid.How is the pressure of the vaporized liquid determined?
Liquid is vaporized into a fixed volume vessel at a measured temperature and barometric pressure. The volume of the flask is measured by filling the flask with water, when open to atm, measure pressure. This will determine the molar mass of the low boiling point liquid.Why method like Kjeldahl and Dumas are used in determining protein content?
The Kjeldahl and Dumas methods. Methods currently used for the determination of the protein content of foodstuffs depend on the determination of nitrogen. The Kjeldahl method, devised in 1883, relies on the conversion of protein nitrogen into the ammonium ion by boiling sulfuric acid in the presence of a catalyst.What are the major sources of error in determining molar mass?
The primary source of error is in the mass measurement, which had a standard deviation of 1.5%. The method could be improved by using a more precise balance to decrease the error in the mass measurements. It is also interesting to note that the molar mass was found to be slightly smaller than the literature value.Why does excess vapor escape from the flask?
When the flask is heated with the volatile liquid inside evaporates and expands to the size of the flask and forces all of the air out of the flask; the excess vapor will escape out of the pinhole as well. The temperature of the vapor in the flask is determined from the temperature of the boiling water.Which gas is liberated in Dumas method?
Dumas method: In Dumas method, a known mass of an organic compound is heated strongly with coarse cupric oxide in an atmosphere of carbon dioxide. Carbon and hydrogen get oxidised to carbon dioxide and water, while the nitrogen present in the organic compound is converted into free nitrogen.How nitrogen is estimated by Kjeldahl method?
The Kjeldahl method or Kjeldahl digestion (Danish pronunciation: [ˈkʰ?lˌtæˀl]) in analytical chemistry is a method for the quantitative determination of nitrogen contained in organic substances plus the nitrogen contained in the inorganic compounds ammonia and ammonium (NH3/NH4+).How is halogen estimated by Carius method?
The Carius halogen method in analytical chemistry is a method for the quantitative determination of halogens in chemical substances. A known mass of an organic compound is heated with fuming nitric acid in the presence of silver nitrate contained in a hard glass tube known as carius tube, in a furnace.What device is best for heating a volatile liquid?
A Bunsen burner is conventional and convenient means for heating of liquids in test tubes and small beakers. However, a naked flame can lead to fires and explosions if such heating is carried out in close proximity of flammable liquids or explosive materials. 
