A) 9.8g of an alcohol A completely reacts with an excess of sodium , and a gas is released. When the reaction ceases the volume of the gas is 1.6L measured at a temperature of 22ºc and under a pressure of 1 bar.

 a- What gas is released in this reaction, how can it be identified?
 b- Write the equation of thr reaction of alcohol with sodium .
 c- Find the molecular formula of A. 

B) The dehydration of alcohol A upon heating and in the presence of sulfuric acid produces only two compounds B and C. Only the molecule of C contains an oxygen atom. The relative density of B with respect to air equals 1.93.
 a- Determine the molecular formulas of the compounds B and C. 

THANKS VERY MUCH 4 YOUR HELP!

http://www.chemguide.co.uk/organicprops/alcohols/sodium.html

http://www.chemguide.co.uk/organicprops/alcohols/dehydration.html The reaction products will depend on the exact alcohol, of course.

A) To answer these questions, we need to consider the reaction between alcohol A and sodium.

a) To identify the gas released in the reaction, we need to consider the reactivity of alcohol A with sodium. Since the reaction produces a gas, it could potentially be hydrogen gas (H2) since many alcohols can react with sodium to produce this gas. To confirm this, we can perform the 'pop' test. The gas collected should be ignited with a flame. If it pops or produces a small explosion, then it is indeed hydrogen gas.

b) The reaction of alcohol A with sodium can be represented by the following equation:
2Alcohol A + 2Na -> 2Alkoxide + H2

c) To find the molecular formula of A, we need to calculate its molar mass using the given mass of alcohol A. The molar mass can be calculated by dividing the given mass (9.8 g) by the number of moles. The number of moles can be determined by dividing the mass by the molar mass.

B) In the given scenario, the dehydration of alcohol A produces two compounds, B and C. Compound C contains an oxygen atom, which suggests that it could be an ether or an aldehyde.

a) To determine the molecular formulas of B and C, we need more information. The relative density of B with respect to air (1.93) does not provide enough information to determine the molecular formula directly. We would need additional data such as melting point, boiling point, infrared spectra, or additional compound analysis to narrow down the possibilities and determine their molecular formulas.