Organic chemistry-some basic principles and techniques practice · Easy

Option A is correct because conformers are isomers that are interconverted through rotation around a single bond. This rotation allows for different spatial arrangements of the atoms.

Option C (Both of these takes place) is correct because homolytic bond fission of CH3Cl results in a methyl radical (CH3•) which is sp2 hybridized and planar.

Option B (Lewis acids) is correct because electrophiles are electron-deficient species that accept electron pairs, which is the definition of a Lewis acid.

Option C (2-methyl butanoic acid) is correct because it has a chiral carbon atom, which is a carbon atom bonded to four different groups, allowing for stereoisomerism.

Option C (Positional isomers) is correct because ${\mathrm{C}_2}{\mathrm{H}_4}\mathrm{B}{\mathrm{r}_2}$ can exist as 1,1-dibromoethane or 1,2-dibromoethane, which are positional isomers.

Option C (Acetonitrile) is correct because Acetonitrile does not have an $sp^2$ hybridized carbon atom.

Option C is correct because optical activity is the property of a chiral substance to rotate the plane of polarized light.

Option A (15) is correct because the sum of sigma and pi bonds in Hex-1,3-dien-5-yne is 15.

Option C (CH3CHClCH2CH3) is correct because it has a chiral carbon atom (a carbon atom bonded to four different groups).

Option C (Both (a) and (b)) is correct because both lead acetate and sodium nitroprusside can be used to detect sulfur in the sodium extract.

The correct answer is Vaccum distillation because it allows for the purification of glycerine at lower temperatures, preventing decomposition.

Option D ($\overline O - C{H_2}C{H_2}N{H_2}$) is the most basic because the negatively charged oxygen atom donates electron density through the inductive effect, increasing the electron density on the nitrogen atom and making it more available for protonation.

Option D is correct because some organic compounds decompose or degrade before reaching their boiling points at normal pressure, necessitating distillation at lower pressures.

Option B is correct because a racemic mixture is a mixture of d- and its l-isomers in equal proportions. This results in no net rotation of plane-polarized light.

Option D (In all states) is correct because optical activity is a property of the molecule itself, and it can be observed in solution, liquid, and crystalline states as long as the chiral center is maintained.

Option A (${\mathrm{C}_6}{\mathrm{H}_7}$) is correct because the empirical formula is C6H7, and the molar mass calculated from the ideal gas law matches this formula.

Option B is correct because a secondary carbon is bonded to two other carbon atoms (alkyl groups).

Option A (Mercapto) is correct because 'mercapto' is the prefix used to name the -SH group in the IUPAC system when it is a substituent.

Option C is correct because H3O+ is a hydronium ion, which is a protonated water molecule and acts as an acid (proton donor), not an electrophile (electron acceptor).

Option B is correct because cyclohexane is a cyclic aliphatic compound, hence alicyclic.

Option B (Ammonium molybdate) is correct because it is the reagent used to identify phosphate ions in the detection of phosphorus.

Option A is correct because Icosane and Heptane have incorrect molecular formulas. The correct formula for Icosane is C20H42 and for Heptane is C7H16.

Option B ($E$ -effect) is correct because the shifting of electrons of a multiple bond under the influence of a reagent is called the electromeric effect, which is also known as the E-effect.

Option A (Acetic Acid) is incorrect. Option A (Urea) is incorrect. Option C (Ethanol) is incorrect. Option B (CH₃COOH) is correct because acetic acid was the first organic compound synthesized from its elements in the laboratory.

Option C (-NH2) is correct because the amino group has a lone pair of electrons that it can donate into a pi system, exhibiting a +R (resonance) effect.

Option D (Eight) is correct because there are eight different structural isomers of pentyl alcohol (${\mathrm{C}_5}{\mathrm{H}_{11}}\mathrm{OH}$).

Option D ($- COO -$) is correct because negatively charged groups generally show +I effect due to the availability of extra electrons.

Option D (All of these) is correct because fractional distillation is used to separate components in petroleum, coal-tar, and crude alcohol based on their boiling points.

Option A (Pentene-2) is correct because geometrical isomerism requires restricted rotation around a double bond and two different groups on each carbon of the double bond, which pentene-2 fulfills.

Option B (Thiocyanate) is correct because when an organic compound containing both nitrogen and sulfur is fused with sodium, it forms sodium thiocyanate (NaSCN).