a) The combustion of an organic compound in the presence of excess oxygen produced a gas , which makes clear lime water turbid. What element can be identified?
b) A sample of this compound is treated with hot molten sodium metal, the obtained mixture is dissolved in water and is then filtered. To a portion of the obtained filtrate an iron ll nitrate solution is added, followed by adding an iron lll nitrate solution and a compound is formed which gives a blue color to the solution.
Write the formula of the compound and give its name.
Thank you.
a) In order to identify the element produced during combustion that makes clear lime water turbid, we can use the following information. The fact that a gas is produced and that it reacts with lime water indicates the presence of carbon dioxide (CO2).
You can perform a simple experiment to confirm this. Firstly, collect the gas that is produced during combustion. Then, pass the gas through clear lime water in a container. If the lime water turns turbid or milky, it indicates the presence of carbon dioxide. This is because carbon dioxide reacts with calcium hydroxide (present in lime water) to form calcium carbonate, which is insoluble and causes the turbidity.
b) To determine the formula and name of the compound formed when a sample of the organic compound is treated with hot molten sodium metal, followed by the addition of iron(II) nitrate solution and iron(III) nitrate solution, we can use the following steps:
1. Treat the organic compound with hot molten sodium metal. This is a typical test for compounds containing a carbonyl group (C=O). The reaction is known as the sodium fusion test. The carbon atoms in the carbonyl group react with sodium metal to produce sodium salts of carboxylic acids.
2. Dissolve the obtained mixture (formed by treating the compound with sodium metal) in water and filter it. This step is done to remove any remaining solids or impurities, leaving behind a clear filtrate.
3. Take a portion of the filtrate and add iron(II) nitrate solution. If a compound is formed, it indicates the presence of a carboxylic acid. In this case, iron(II) carboxylate is formed, which is green in color.
4. Add iron(III) nitrate solution to the same solution from step 3. If a blue color is observed, it indicates the presence of a compound called Prussian blue. Prussian blue is formed when iron(II) carboxylate reacts with iron(III) nitrate.
Therefore, the formula of the compound is Fe4[Fe(CN)6]3 and its name is Prussian blue.
Note: It is important to take precautionary measures and perform these experiments in a controlled laboratory setting as they involve the use of chemicals and potentially hazardous reactions.
a) The gas produced that makes clear lime water turbid is carbon dioxide (CO2). When an organic compound undergoes combustion in the presence of excess oxygen, carbon in the compound combines with oxygen to form carbon dioxide gas.
b) The formula of the compound formed when iron II nitrate solution is added to the filtrate is Fe(SCN)2. This compound is called iron(II) thiocyanate.