A given compound has the following solubility properties. At room temperature, it is soluble in diethyl ether but insoluble in both ethanol and water. At higher temperatures, it is soluble in both diethyl ether and ethanol, but insoluble in water. Propose a procedure for purifying this compound by recrystallization.

See explanation

Explanation:

If we desire to recrystallize the given compound then we must do the following;

1) Add the compound to ethanol and heat the system

2) As the solute dissolves, the solution is allowed to cool

3) The solution may be seeded or the vessel scratched to aid crystallization.

4) The pure crystals are now filtered out, washed and dried.

Remember that recrystallization has to do with dissolving a solute in a solvent in which it is only soluble at high temperature but insoluble at low temperature.

The solvent dissolves the impure solute while pure crystals emerges as the temperature decreases.

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

the correct answer is:

a. formation of precipitation