34 + Interview Questions in PURIFICATION-AND-CHARATERIZATION-OF-ORGANIC-COMPOUNDS IN GENERAL AWARENESS Page 1 InterviewSolution

1.	Percentage of `Se` (atomic mass `= 78.4 u`) in peroxidase anhydrase enzyme is `0.5%` by mass. The minimum molecular mass of peroxidase anhydrase enzyme isA. `136xx10^(4)`B. `568xx10^(3)`C. `15.28`D. `568 xx 10^(4)`
Answer» Correct Answer - D Since minimum molecular mass of enzyme corresponds to minimum number of Se atoms, i.e., just one atom of Se, we have `%` of `Se = ((At.mass)_(se))/(("Min.mol.mass")_("Enzyme")) xx 100%` Thus, minimum molecular mass of enzyme `=((At.mass)_(se))/(%Se) xx 100%` `=(78.4u)/(0.5%) xx 100%` `= 15680 u = 1567 xx 10^(4)`

Discussion

2.	In Carius tube, the compound `ClCH_(2)COOH` was heated with fuming `HNO_(3)` and `AgNO_(3)`. After filtration and washing, a white precipitate was formed. The precipitate is ofA. `AgCl`B. `AgNO_(3)`C. `Ag_(2)SO_(4)`D. `CH_(2)ClCO OAg`
Answer» Correct Answer - A `Na + Cl overset(Delta)underset(("from" o .c.))rarr NaCl overset(AgNO_(3))rarr underset("White ppt.")(AgCl +) NaNO_(3)`

Discussion

3.	By the process of cystallization, we convert an impure compound into its crystals. The choice of the solvent is very crucial in this operations. Which of the following conditions must be fulfilled by the selected solvent? (i) It should not react chemically with the impure organic compund. (ii) Is should be the one in which the solid organic compound is very soluble at room temperature. (iii) The impurities should not dissolve at all in the solvent. (iv) If the impurities dissolve, they should be soluble to such an extent that they remain in the filtrate (mother liquor) upon crystallization.A. (i), (iii), (iv)B. (i), (ii), (iii)C. (i), (ii), (iv)D. (i), (ii), (iii), (iv)
Answer» Correct Answer - D Condition `(ii)` must be fulfilled so that excess of the organic compound is thrown out as crystals on cooling the hot solution. If the impurities are more soluble in the cold solvent than is the compound being purified, then they will almost certainly remain in the solution in the mother liquor (the residual cold solution from which the compound crystallizes). The impurities which are less soluble will also probably not be precipitate on cooling because they are unlikely to be present in sufficiently high concentration to form a saturated solution even at lower temperature. Moreover, even if some impurity is deposited with the pure compound on cooling, its proportion will be considerably less than in the original crude material, and it will be completely removed by further recrystallization.

Discussion

4.	In case the difference in solubilty ofhte two substances in the solvent is not very marked, ………….., involving a series of repeated vrystallizations, is carried out.A. fractional crystallizationB. vacuume crystallizationC. ultra crystallizationD. multiple crystallization
Answer» Correct Answer - A In this process, crystallization is repeated a number of times.

Discussion

5.	For the purification of organic compounds, the latest technique followed isA. steam distillationB. chromatographyC. fractional crystallizationD. sublimation
Answer» Correct Answer - B The most widely used latest methods of separation of the desired compound from the impurities are the chromatographic methods. Chromatography is the technique for the separation of a mixture of solutes brought about by the dynamic partition of distribution of dissolved or dispersed substances between two immiscible phases, one of which is moving past the other.

Discussion

6.	The solvent for crystallization is usually selected by trial and error using small samples. The commonest solvents are water, alcohol or methylated spirits, glacial acetic acid, ete. Which of the following solvents are least describle ? (i) Ether (ii) Acetone (iii) Benzene (iv) PetrolA. (ii), (iii)B. (i), (iv)C. (i), (iii)D. (iii), (iv)
Answer» Correct Answer - B The high inflammability of ether and petrol makes them least desirable. Sometimes a mixture of two solvents is chosen.

Discussion

7.	Which of the following types of chromatography is refered to as liquid/liquid chromatography?A. Paper chromatographyB. Gas chromatographyC. Thin layer chromatographyD. Column chromatography
Answer» Correct Answer - A Because in paper chromatography both the mobile and stationary phases are liquids. Column and thin layer chromatography are examples of liquid/solid chromatography as the mobile phase is a liquid while the stationary phase is a solid.

Discussion

8.	Which of the following solvents is used to separated benzoic acid and anthracene by the process of filtration ?A. Cold waterB. Hot waterC. EtherD. Benzene
Answer» Correct Answer - B Benzoic acid is appreciably soluble in hot water but only sparingly soluble in cold water, while anthracene is insoluble in water.

Discussion

9.	Which of the following technique is most suitable for the purification of cyclohexanone from a mixture containing benzoic acid, isoamyl alcohol, cyclohexane, and cyclohexanone?A. CrystallizationB. SublimationC. Gas chromatographyD. `IR` spectrography
Answer» Correct Answer - C Gas chromatography is the newest and the most important type of chromatography. Unlike the other types, it enables us to make accurate quantitative analysis of mixtures of gases, liquids, and volatile solids. It is quite extremely sensitive and very versatile in its application. By using gas chromatography, it is possible to separate complex mixtures of aliphatic and aromatic hydrocarbons (found in petrol and natural gas). Fatty acids and esters are other series (often difficult to separate of distinguish by chemical methods) which are amenable to gas chromatography. Thus, the method can be applied to the mixtures of fats, waxes, oils flavors, and perfumes. Gas chromatography can also be used to purify small amounts of individual volatile substances and as a test of the purity of a substance, since the presence of even a trace of impurity can be readily defected.

Discussion

10.	Which of the following types of chromatography enables us to make accurate quantitative analysis of the mixtures of gases, liquids, and volatile solids?A. Paper chromatographyB. Gas chromatographyC. Thin layer chromatographyD. Column chromatography
Answer» Correct Answer - B Gas chromatography is the newest and the most important type of chromatography. It is quick, extremely sensitive, and very versatile in its application. Here, a small quantity of the volatile mixture is injected in to a steady stream of an unreactive gas which acts as carrier. On passing through the column, the vapors of comstituents of the mixture undergo adsorption of partition to different extents.

Discussion

11.	A mixture of camphor and benzoic acid can be separated byA. sublimationB. fractional distillationC. chemical methodD. extraction with a solvent
Answer» Correct Answer - C Benzoic acid is a carboxylic acid, and thus dissolves in `NaHCO_(3)(aq.)` solution while camphor is a ketone and, hence, remains insoluble. Filtration of solution recovers camphor. Benzoic acid can be precipitated from its salt by acidification.

Discussion

12.	Fractional distillation is a process by which the separation of different from a liquid mixture is carried out by making use of difference ofA. solubilityB. boiling pointC. melting pointD. density
Answer» Correct Answer - B It is employed provided the difference between boiling points is less than `30^(@)C`.

Discussion

13.	Rectified spirit contains about `95%` alcohol (b.p. `351 K`) and `5%` water (b.p. `373 K`). The two components can be separated byA. simple distillationB. azeotropic distillationC. fractional distillationD. steam distillation
Answer» Correct Answer - B The two components cannot be separated from the mixture by distillation no matter how efficient the fractionating column used is, even though their boiling points differ by `22 K`. At the given composition, alcohol and water form a constant boiling mixture called azeotrope, which distils like a pure liquid at a certain constant temperature. To remove water from such a mixture (binary azeotrope), we perform fractional distillation using a suitable volatile solvent. The process is called azeotropic distillation. In the present case, the process is carried out with a suitable amount of benzene. The first fraction obtained at `331.8 K` is a ternary azeotrope containing mostly water, some alcohol, and some benzene. The second fraction distilled out at `341.2 K` is a binary azeotrope containing some alcohol and remaining benzene. The third fraction distilling at `351 K` is absolute alcohol.

Discussion

14.	A mixture contains four solid organic compounds `A, B, C` and `D`. On heating, only `C` changes from solid to vapor state. `C` can be separated from the rest in the mixture byA. sublimationB. distillationC. crystallizationD. differential extraction
Answer» Correct Answer - A Sublimation is the conversion of a solid directly into vapor and subsequent condensation, without melting.

Discussion

15.	Which of the following is used to separated two immiscible liquids ?A. Buchner funnelB. Vacuum funnelC. Separating funnelD. Fluted funnel
Answer» Correct Answer - C Separating funnel has a stop cock at the bottom to run out the two distinct layers.

Discussion

16.	Which of the following organic liquids can be purified by steam distillation ? (i) Aniline (ii) Turpentine oil (iii) Essential oils (iv) GlycerineA. (i), (ii), (iii), (iv)B. (ii), (iii), (iv)C. (ii), (i), (iv)D. (i), (ii), (iii)
Answer» Correct Answer - D Impure glycerine is purified by vacuum distillation while others are steam volatile, and thus purified by steam distillation.

Discussion

17.	A liquid which is immiscible in water and has a vapor presure of `10-15 mm Hg` at `373 K` can be conveniently purified byA. fractional distillationB. steam distillationC. vacuum distillationD. simple distillation
Answer» Correct Answer - B Such a liquid is volatile in steam.

Discussion

18.	Which of the following compounds are steam volatile ? (i) para-Hydroxyacetophenone (ii) ortho-Nitrophenol (iii) ortho-Hydroxyacetophenone (iv) para-NitrophenolA. (ii), (iii)B. (i), (iv)C. (i), (ii)D. (iii), (iv)
Answer» Correct Answer - A Because of intramolecular hydrogen bonding (chelation), o-hydroxyacetophenone and o-nitrophenol are steam volatile.

Discussion

19.	The empirical formula of an acid is `CH_(2)O_(2)`, the probable molecular formula of acid may beA. `CH_(2)O`B. `CH_(2)O_(2)`C. `C_(2)H_(4)O_(2)`D. `C_(3)H_(6)O_(4)`
Answer» Correct Answer - B The simplest saturated monocarboxylic acid is formic acid: `H-overset(O)overset(\|\|)(C)-OH`

Discussion

20.	The empirical formula of a compound is `CH_(2)`. IF one mole of the compound has a mass of `42 g`, its molecular formula isA. `CH_(2)`B. `C_(3)H_(6)`C. `C_(2)H_(2)`D. `C_(3)H_(8)`
Answer» Correct Answer - B Molecular formula `= n` (Empirical formula) `n = ("Molecular mass")/("Empirical formula mass") = (42 u)/(14 u) = 3` `:. M.F. = 3(CH_(2)O) = C_(3)H_(6)O_(3)`

Discussion

21.	An organic compound contains `C = 40%, H = 13.33%`, and `N = 46.67%`. Its empirical formula will beA. `CHN`B. `C_(3)H_(7)N`C. `C_(2)H_(2)N`D. `CH_(4)N`
Answer» Correct Answer - D Considering `100 g` of the compound, we have `m_(C ) = 40 g, m_(H) = 13.33 g`, and `m_(N) = 46.67 g` Thus, the ratio of moles will be `n_(C ):n_(H):n_(N) = (40)/(12) : (13.33)/(1) : (46.67)/(14)` `= 3.33 : 13.33 : 3.33` `= (3.33)/(3.33) : (13.33)/(3.33) : (3.33)/(3.33)` `= 1 : 4 : 1` Thus, the empirical formula is `CH_(4)N`.

Discussion

22.	`0.1 mol` of a carbonhydrate with empirical formula `CH_(2)O` contains `1 g` of hydrogen. What is its molecular formula?A. `C_(5)H_(10)O_(5)`B. `C_(3)H_(6)O_(3)`C. `C_(4)H_(8)O_(4)`D. `C_(6)H_(12)O_(6)`
Answer» Correct Answer - A `0.1` mol of carbohydrate contains `1 g H`, thus, `1` mol of carbohydrate will contain `10 g H`. In other words, `1` molecule contains `10 "amu" H`. The only formula that confirms is `C_(5)H_(10)O_(5)`.

Discussion

23.	`0.0833 `mol of carbohydrate of empirical formula `CH_(2)O` contain `1 g ` of hydrogen. The molecular formula of the carbohydrate isA. `C_(6)H_(12)O_(6)`B. `C_(5)H_(10)O_(5)`C. `C_(3)H_(4)O_(3)`D. `C_(6)H_(12)O_(5)`
Answer» Correct Answer - A `0.833 mol` of carbihydrate contains `10 g` hydrogen. Thus, `1 mol` of the compound will certain `(10 g)/(0.833 mol) = 12 g mol^(-1)` This implies that `1` molecule of carbohydrate contains `12 u` of `H (or (12 u)/(1 u "atom"^(-1)) = 12 at oms of H)` `:.` Molecular formula `= C_(6)H_(12)O_(6)`

Discussion

24.	Absolute alcohol is prepared byA. fractional distillationB. vacuum distillationC. Steam distillationD. azeotropic distillation
Answer» Correct Answer - D Pure ethanol is known as absolute alcohol. Although more expensive than a binary azeotrope containing `95%` alcohol and `5%` water, it is available for use when specifically require, For preparing it, we distil the mixture of `95%` alcohol and `5%` water with benzene, called azeotropic distillation.

Discussion

25.	The product of the Reimer-Tiemann reaction is amixture of `o-`hydroxybenzaldehyde (major product) and `p-hydroxy-benzaldehyde (minor product). The constituents of the mixture are best separated byA. crystallizationB. distillationC. Steam distillationD. sublimation
Answer» Correct Answer - C On account of intramolecular hydrogen bonding, o-hydroxybenzaldehyde is sparingly soluble in water and possesses low vapor pressure. Being steam volatile, it can be separated effectively from its isomer by steam distillation.

Discussion

26.	The ammonia evolved from the treatment of `0.30g ` of an organic compound for the estimation of nitrogen was passed in `100 mL` of `0.1M` sulphuric acid. The excess of acid required `20mL` of `0.5 M` sodium hydroxide solution for complete neutralization. The organic compound isA. thioureaB. benzamideC. ureaD. acetamide
Answer» Correct Answer - C Normality `= n xx` Molarity (`n = 2` for `H_(2)SO_(4), n = 1` for `NaOH`) Total milliequivalent of `NH_(3) =` (Total Milliequivalent of `H_(2)SO_(4)) -` (Milliequivalent of `H_(2)SO_(4)` neutralized by `NaOH`) `= (20) - (10) = 10` Equivalent of `NH_(3) = ("Milliequi valent")/(1000) = (10)/(1000) = 10^(-2)` `:.` Mass of `N = (n_(N))("Molar mass")` `= (10^(-2))(14) = 0.14 g` `% N = (m_(N))/(m_(o .c.)) xx 100% = (0.149)/(0.30 g) xx 100%` `= 46.6%` now, we calculate the percentage of `N` in every compound to fix the answer. Thiourea `(H_(2)NCSNH_(2)) : %N = (28)/(76) xx 100% = 31.84` benzamide `(C_(6)H_(5)CONH_(2)): % N = (14)/(121) xx 100% = 11.5` Urea `(H_(2)NCONH_(2)): % N = (28)/(60) xx 100% = 46.6` Acetamide `(CH_(3)CONH_(2)): % N = (14)/(59) xx 100% = 23.7` Hence, the given organic compound is urea.

Discussion

27.	`0.1914 g` of an organic acid is dissolved in about `20 mL` of water. `25 mL` of `0.12 N NaOH` is required for complete neutralization of the acid solution. The equivalent mass of the acid isA. `65.0`B. `64.0`C. `62.5`D. `63.8`
Answer» Correct Answer - D According to the law of equivalence, `("Milliequival ents")_(NaOH) = ("Milliequi valents")_(o .acid)` `= (0.12)(25) = 3` `:.` Equivalents of organic acid `= (3)/(1000)` This implies that `3 xx 10^(-3)` equivalents of acid weigh `0.1914 g`. Thus, `1` equivalent of acid will weigh `(0.1914 g)/(3 xx 10^(-3) eq) = 63.8 g eq^(-1)` Hence, the equivalent mass of acid is `63.8 u`.

Discussion

28.	An organic compound made up of `C, H`, and `N` contains `20%N`. The molecular mass of the organic compound isA. `100 u`B. `65 u`C. `140 u`D. `70 u`
Answer» Correct Answer - D As per the information, we can only find out the minimum molecular mass of the compound considering one `N` atom per molecule. Thus, `%` of `N = ("Atomic mass of N")/("Minimum molecular mass of compound") xx 100%` `20% = (14 u)/("Minimum molecular mass") xx 100%` or Minimum molecular mass of compound `= (14 u)/(20 %) xx 100%` `=70 u`

Discussion

29.	Acetanilde `(C_(6)H_(5)NHCOCH_(3))` is sparingly soluble in cold water but readily soluble in boiling water. It is usually purifies byA. chromatographyB. crystallizationC. sublimationD. distillation
Answer» Correct Answer - B It is one of the most commonly used technique for the purification of solid organic compounds. The impure compound is dissolved in a suitable solvent in which it is sparingly soluble at room temperature but appreciably soluble at higher temperature.

Discussion

30.	During the testing for phosphorus in organic compounds, a yellow solution or precipitate is formed due to the formation ofA. ammonium phosphateB. ammonium molybdateC. ammonium phosphomolybdateD. sodium phosphate
Answer» Correct Answer - C The yellow solution or precipitate is of ammonium phosphomolydate `(NH_(4))_(3)[PO_(4).12M0O_(3)]` or `[NH_(4)]_(3) [PMo_(12)O_(40)]`

Discussion

31.	If `0.32 g` of an organic compound containing sulphur produces `0.233 g` of `BaSO_(4)`, the percentage of sulphur in the compound isA. `15`B. `10`C. `20`D. `25`
Answer» Correct Answer - B `%` of `S = (32)/(233) xx (m_(BaSO_(4)))/(m_(o .c.)) xx 100%` `= (32)/(233) xx (0.233)/(0.32) xx 100% = 10%`

Discussion

32.	The percentage of oxygen in an organic compound can be determined by converting `O` of the compound quantitatively into (i) `CO_(2)` (ii) `I_(2)O_(5)` (iii) `I_(2)` (iv) `CO`A. (ii), (iv)B. (i), (ii)C. (iii), (iv)D. (i), (iii)
Answer» Correct Answer - D The percentage of oxygen in the organic compound can be determined from the amount of `CO_(2)` or `I_(2)` produced. Organic compound `underset (Delta) overset(N_(2))rarr O_(2) +` other gaseous porducts `O_(2) + 2C rarr 2CO` `5CO + I_(2)O_(5) rarr 5CO_(2) + I_(2)`

Discussion

33.	Nitric acid is added to sodium fusion extract and the solution is boiled before adding silver nitrate for testing halogens becauseA. the extract is alkaline and thus must be neutralized.B. intric acid decomposes sodium cyanide or sodium sulphide (if present) to hydrogen cyanide and hydrogen sulphide gases, respectively.C. nitric acid oxidizes halogen to halide ion.D. nitric acid dissolves silver nitrate.
Answer» Correct Answer - B `NaCN + HNO_(3) rarr HCN + NaNO_(3)` `Na_(2)S + HNO_(3) rarr H_(2)S + NaNO_(3)`

Discussion

34.	An organic compound having molecular mass `60` is found to contain `C = 20%, H = 6.67%`, and `N = 46.67%`, while rest is oxygen. On heating, it gives `NH_(3)` along with a solid residue. The solid residue gives violet color with alkaline copper sulphate solution. The compounds isA. `(NH_(2))_(2)CO`B. `CH_(3)CONH_(2)`C. `CH_(3)NCO`D. `CH_(3)CH_(2)CONH_(2)`
Answer» Correct Answer - A Out of given organic compounds, only urea has molecular mass `= 60 u` and percentage of `% N = 46.67 %`. When gently heated, urea loses ammonia to form biuret: `(NH_(2))_(2) CO hArr NH_(3) + HNO overset((NH_(2))_(2)CO)rarrH_(2)NCONHCONH_(2)` or `H_(2)NCO-NH_(2)+H-NHCONH_(2) overset(-NH_(3))rarr underset("Biuret")(H_(2)NCONHCONH_(2))` When an aqueous biuret solution is treated with sodium hydroxide solution and a drop of copper sulphate solution, a violetcolor is produced. This is known as the biuret reaction which is characteristic of compounds containing the grouping `-CONH -`, e.g., proteins.

Discussion

Explore topic-wise InterviewSolutions in .

Percentage of `Se` (atomic mass `= 78.4 u`) in peroxidase anhydrase enzyme is `0.5%` by mass. The minimum molecular mass of peroxidase anhydrase enzyme isA. `136xx10^(4)`B. `568xx10^(3)`C. `15.28`D. `568 xx 10^(4)`

In Carius tube, the compound `ClCH_(2)COOH` was heated with fuming `HNO_(3)` and `AgNO_(3)`. After filtration and washing, a white precipitate was formed. The precipitate is ofA. `AgCl`B. `AgNO_(3)`C. `Ag_(2)SO_(4)`D. `CH_(2)ClCO OAg`

In case the difference in solubilty ofhte two substances in the solvent is not very marked, ………….., involving a series of repeated vrystallizations, is carried out.A. fractional crystallizationB. vacuume crystallizationC. ultra crystallizationD. multiple crystallization

For the purification of organic compounds, the latest technique followed isA. steam distillationB. chromatographyC. fractional crystallizationD. sublimation

Which of the following types of chromatography is refered to as liquid/liquid chromatography?A. Paper chromatographyB. Gas chromatographyC. Thin layer chromatographyD. Column chromatography

Which of the following solvents is used to separated benzoic acid and anthracene by the process of filtration ?A. Cold waterB. Hot waterC. EtherD. Benzene

Which of the following technique is most suitable for the purification of cyclohexanone from a mixture containing benzoic acid, isoamyl alcohol, cyclohexane, and cyclohexanone?A. CrystallizationB. SublimationC. Gas chromatographyD. `IR` spectrography

Which of the following types of chromatography enables us to make accurate quantitative analysis of the mixtures of gases, liquids, and volatile solids?A. Paper chromatographyB. Gas chromatographyC. Thin layer chromatographyD. Column chromatography

A mixture of camphor and benzoic acid can be separated byA. sublimationB. fractional distillationC. chemical methodD. extraction with a solvent

Fractional distillation is a process by which the separation of different from a liquid mixture is carried out by making use of difference ofA. solubilityB. boiling pointC. melting pointD. density

Rectified spirit contains about `95%` alcohol (b.p. `351 K`) and `5%` water (b.p. `373 K`). The two components can be separated byA. simple distillationB. azeotropic distillationC. fractional distillationD. steam distillation

A mixture contains four solid organic compounds `A, B, C` and `D`. On heating, only `C` changes from solid to vapor state. `C` can be separated from the rest in the mixture byA. sublimationB. distillationC. crystallizationD. differential extraction

Which of the following is used to separated two immiscible liquids ?A. Buchner funnelB. Vacuum funnelC. Separating funnelD. Fluted funnel

Which of the following organic liquids can be purified by steam distillation ? (i) Aniline (ii) Turpentine oil (iii) Essential oils (iv) GlycerineA. (i), (ii), (iii), (iv)B. (ii), (iii), (iv)C. (ii), (i), (iv)D. (i), (ii), (iii)

A liquid which is immiscible in water and has a vapor presure of `10-15 mm Hg` at `373 K` can be conveniently purified byA. fractional distillationB. steam distillationC. vacuum distillationD. simple distillation

Which of the following compounds are steam volatile ? (i) para-Hydroxyacetophenone (ii) ortho-Nitrophenol (iii) ortho-Hydroxyacetophenone (iv) para-NitrophenolA. (ii), (iii)B. (i), (iv)C. (i), (ii)D. (iii), (iv)

The empirical formula of an acid is `CH_(2)O_(2)`, the probable molecular formula of acid may beA. `CH_(2)O`B. `CH_(2)O_(2)`C. `C_(2)H_(4)O_(2)`D. `C_(3)H_(6)O_(4)`

The empirical formula of a compound is `CH_(2)`. IF one mole of the compound has a mass of `42 g`, its molecular formula isA. `CH_(2)`B. `C_(3)H_(6)`C. `C_(2)H_(2)`D. `C_(3)H_(8)`

An organic compound contains `C = 40%, H = 13.33%`, and `N = 46.67%`. Its empirical formula will beA. `CHN`B. `C_(3)H_(7)N`C. `C_(2)H_(2)N`D. `CH_(4)N`

`0.1 mol` of a carbonhydrate with empirical formula `CH_(2)O` contains `1 g` of hydrogen. What is its molecular formula?A. `C_(5)H_(10)O_(5)`B. `C_(3)H_(6)O_(3)`C. `C_(4)H_(8)O_(4)`D. `C_(6)H_(12)O_(6)`

`0.0833 `mol of carbohydrate of empirical formula `CH_(2)O` contain `1 g ` of hydrogen. The molecular formula of the carbohydrate isA. `C_(6)H_(12)O_(6)`B. `C_(5)H_(10)O_(5)`C. `C_(3)H_(4)O_(3)`D. `C_(6)H_(12)O_(5)`

Absolute alcohol is prepared byA. fractional distillationB. vacuum distillationC. Steam distillationD. azeotropic distillation

The product of the Reimer-Tiemann reaction is amixture of `o-`hydroxybenzaldehyde (major product) and `p-hydroxy-benzaldehyde (minor product). The constituents of the mixture are best separated byA. crystallizationB. distillationC. Steam distillationD. sublimation

`0.1914 g` of an organic acid is dissolved in about `20 mL` of water. `25 mL` of `0.12 N NaOH` is required for complete neutralization of the acid solution. The equivalent mass of the acid isA. `65.0`B. `64.0`C. `62.5`D. `63.8`

An organic compound made up of `C, H`, and `N` contains `20%N`. The molecular mass of the organic compound isA. `100 u`B. `65 u`C. `140 u`D. `70 u`

Acetanilde `(C_(6)H_(5)NHCOCH_(3))` is sparingly soluble in cold water but readily soluble in boiling water. It is usually purifies byA. chromatographyB. crystallizationC. sublimationD. distillation

During the testing for phosphorus in organic compounds, a yellow solution or precipitate is formed due to the formation ofA. ammonium phosphateB. ammonium molybdateC. ammonium phosphomolybdateD. sodium phosphate

If `0.32 g` of an organic compound containing sulphur produces `0.233 g` of `BaSO_(4)`, the percentage of sulphur in the compound isA. `15`B. `10`C. `20`D. `25`

The percentage of oxygen in an organic compound can be determined by converting `O` of the compound quantitatively into (i) `CO_(2)` (ii) `I_(2)O_(5)` (iii) `I_(2)` (iv) `CO`A. (ii), (iv)B. (i), (ii)C. (iii), (iv)D. (i), (iii)