Question

4. Know the eluting power/polarity of solvents for column chromatography 5. Know what constitutes a halogenated compound vs a non-halogenated compound 6. Know the factors involved in determining the rate of an Sn1 reaction

Answer 1

4. The eluting power of a substance from the column depends on the polarity of the substance eluting from the column.

If a substance is polar, it requires polar eluent to pass through the stationary phase (usually silica).

If a substance is nonpolar, it requires nonpolar eluent to pass through the stationary phase (usually silica).

The polarity of solvents for column chromatography depends on the ratio of polar solvent in the eluent (a mixture of polar and nonpolar solvents, for example, a mixture of hexane and ethyl acetate).

5. The constitutes of halogenated compounds: Carbon, hydrogen, chlorine/bromine/iodine.

The constitutes of non-halogenated compounds: Carbon, hydrogen, nitrogen, and oxygen.

6. The rate of SN1 reaction depends only on the concentration of reactants, i.e. alkyl halides.

i.e. Rate of SN1 reaction ? [alkyl halide]

Explanation; The removal of leaving group (Cl or Br or I) from the reactant, i.e. alkyl halide is the slow step. In this step, a carbocation generates. The attack of a nucleophile on the carbocation is the fast step. Hence, the rate of SN1 reaction depends only on the concentration of reactant, i.e. alkyl halide.