Description : 0.257g of organic substance was heated with conc. sulphuric acid and then distilled with excess of strong alkali .the ammonia gas evolved was absorbed in 50ml of .1M HCl which required 23.2ml of c for neutralization at the end of the process. Determine the % of nitrogen in the compound ?
Last Answer : A. Vol of 0 .1M HCl taken = 50ml Vol of .1MNaOH used for neutralization of unused acid=23.2ml Now, 23.2 ml of .1MNaOH =23.2ml of .1MHCl Vol of .1MHCl unused=23.2ml Vol of .1MHCl required ... NH3 solution contain nitrogen = 14*26.8/10*1000 Percentage of Nitrogen=14*26.8*100/10*1000*.257 =14.6%
Description : In DNA and RNA nitrogen is present in the ring system. Can Kjeldahl method can be used for the estimation of nitrogen present in these ?give reasons
Last Answer : In DNA and RNA nitrogen is present in heterocyclic rings. Kjeldahl method can not be used to estimate nitrogen present in the ring because cannot be completely converted in to (NH4)2SO4 during digestion. Therefore Kjeldahl method cannot be used to estimate nitrogen present in DNA and RNA.
Description : Kjeldahl nitrogen is a mixture of A. Ammonia and nitrogen B. Nitrogen and organic nitrogen C. Organic nitrogen and ammonia D. All the above
Last Answer : ANS: D
Description : In Dumas’ method for estimation of nitrogen, 0.3g of an organic compound gave 50mL of nitrogen collected at 300K temperature and 715mm pressure. Calculate the percentage composition of nitrogen in the compound. (Aqueous tension at 300K=15 mm).
Last Answer : Volume of nitrogen collected at 300K and 715mm pressure is 50 mL Actual pressure = 715-15 =700 mm Volume of Nitrogen at STP=273*700*50/300*760 =41.9 ml 22400 ml of Nitrogen at STP weighs = 28 g 41.9 ml of Nitrogen weighs = 28*41.9/22400 g % of Nitrogen = 28*41.9*100/22400*0.3 = 17.45 %
Description : In an estimation of sulphur by carius method 0.468 g of an organic compound gave 0.668 g of barium sulphate. Find the percentage of sulphur in the compound.
Last Answer : Mass of the compound = 0.468 g Mass of the barium sulphate = 0.668 g % of sulphur = 32 X Mass of barium sulphate X 100/ 233 X Mass of the compound = 32 x 0.668x100/ 233 x0.468 = 19.60 %
Description : What is the principle of Dumas method for the estimation of N in the organic compound?
Last Answer : In Dumas method , Nitrogen present in organic compound on heating with CuO release free nitrogen gas ,which collected by the downword displacement of KOH. From the voiume of nitrogen gas collected at STP, Nitrogen could be estimated.
Description : 0.3780g of organic chloro compound gave 0.5740g of silver chloride in carius estimation .Calculate the percentage of chlorine present in the compound.
Last Answer : % of chlorine = 35.5*mass of AgCl formed * 100/143.5 * mass of the substance = 35.5*0.5740*100/143.5*0.3780 = 19.6 %
Description : Kjeldahl method is used to determine
Last Answer : Ans. Total N of soil
Description : The best method of determining sulphur in crude oil is by the __________ method. (A) Kjeldahl (B) Dumas (C) Bomb calorimeter (D) Junkers calorimeter
Last Answer : (C) Bomb calorimeter
Description : The concentration (weight %) of nitric acid produced by the oxidation of ammonia and absorption of nitrogen oxides with water is about __________ percent. (A) 60 (B) 30 (C) 95 (D) 100
Last Answer : (A) 60
Description : For organic compounds, group contribution method can be used for the estimation of (A) Critical properties (B) Specific gravity (C) Specific volume (D) Thermal conductivity
Last Answer : (A) Critical properties
Description : Nitrogen fixation is a process of - (1) Assimilation of nitrate (2) Utilisation of nitrogen gas (3) Conversion of organic nitrogen to proteins (4) Conversion of molecular nitrogen to ammonia
Last Answer : (4) Conversion of molecular nitrogen to ammonia Explanation: Nitrogen fixation is a process by which nitrogen in the Earth's atmosphere is converted into ammonia (NH3) or other molecules available ... plants as nutrients. The conversion of organic nitrogen to proteins is achieved in Nitrogen cycle.
Description : In sewage having fully oxidised organic matter, the nitrogen exists in the form of A. Nitrites B. Nitrates C. Free ammonia D. Aluminoid nitrogen
Last Answer : ANS: B
Description : Nitrogen fixation is a process of (1) Assimilation of nitrate (2) Utilisation of nitrogen gas (3) Conversion of organic nitrogen to proteins (4) Conversion of molecular nitrogen to ammonia
Last Answer : Conversion of molecular nitrogen to ammonia
Description : Compound (A) when reacted with PCl5 and then with ammonia gave (B). Compound (B) when treated with bromine and NaOH, produced (C). Compound (C) on treatment with NaNO2/HCl at 0°C and then boiling with H2O ... Compound (A) is (a) o-Toluic acid (b) o-Chlorotoluene (c) m-Toluic acid (d) o-Bromotoluene
Last Answer : o-Toluic acid
Description : 100 mL of 0.3 M acetic acid is shaken with 0.8 g wood charcoal. The final concentration of acetic acid in the solution after adsorption is 0.125 M. Th
Last Answer : 100 mL of 0.3 M acetic acid is shaken with 0.8 g wood charcoal. The final concentration of acetic acid in the ... g` C. `1.31 g` D. `0.131 g`
Description : If mass of `KHC_(2)O_(4)` (potassium acid oxalate) required to reduce 100 mL of 0.02 M `KMnO_(4)` in acidic medium is x g and to neutralise 100 mL of
Last Answer : If mass of `KHC_(2)O_(4)` (potassium acid oxalate) required to reduce 100 mL of 0.02 M `KMnO_(4)` in acidic ... y is 1g D. If x is 11g then y is 5.5g
Description : One gram of `Na_(3)AsO_(4)` is boiled with excess of solid `KI` in presence of strong `HCl`. The iodine evolved is absorbed in `KI` solution and titra
Last Answer : One gram of `Na_(3)AsO_(4)` is boiled with excess of solid `KI` in presence of strong `HCl`. The iodine evolved ... B. 38.4 mL C. 24.7 mL D. 30.3 mL
Description : Under what condition, the heat evolved or absorbed in a reaction is equal to its free energy change?
Last Answer : Ans. As ΔG = ΔH – TΔS. Thus, ΔG = ΔH only when either the reaction is carried out at 0^0 K or the reaction is not accompanied by any entropy change, i.e., ΔS = 0
Description : Under what condition, the heat evolved/absorbed in a reaction is equal to its free energy change?
Last Answer : Ans. In ∆G = ∆H – T. ∆S, when reaction is carried out at 0 K or ∆S = 0, then ∆G = ∆H.
Description : Respiratory quotient (RQ) is equal to a. Volume of CO2 evolved/Volume of O2 absorbed b. Volume of CO2 absorbed/Volume of O2 evolved c. Volume of CO2 evolved/Volume of O2 evolved d. Volume of CO2 absorbed/Volume of O2 absorbed
Last Answer : a. Volume of CO2 evolved/Volume of O2 absorbed
Description : Heat evolved/absorbed during conversion of a substance from one allotropic form to another is termed as the heat of (A) Fusion (B) Vaporisation (C) Transition (D) None of these
Last Answer : (C) Transition
Description : 0.037g of an alcohol, R-OH was added to `CH_(3)MgBr` and the gas evolved measured 11.2 mL at STP. The Molecular mass of R-OH will be .
Last Answer : 0.037g of an alcohol, R-OH was added to `CH_(3)MgBr` and the gas evolved measured 11.2 mL at STP. The Molecular ... will be . A. 47 B. 79 C. 74 D. 77
Description : If the total amount of a drug present in the body at a given moment is 2.0 g and its plasma concentration is 25 μg/ml, its volume of distribution is: A. 100 L B. 80 L C. 60 L D. 50 L
Last Answer : B. 80 L
Description : 2 If the total amount of a drug present in the body at a given moment is 2.0 g and its plasma concentration is 25 μg/ml, its volume of distribution is: A. 100 L B. 80 L C. 60 L D. 50 L
Description : If the total amount of a drug present in the body at a given moment is 2.0 g and its plasma concentration is 25 μ g/ml, its volume of distribution is: A. 100 L B. 80 L C. 60 L D. 50 L
Description : Urea is widely used as a fertilizer because it (a) is an organic compound (b) contains very high amounts of nitrogen (c) is soluble in water (d) mixes easily with soil
Last Answer : Ans:(b)
Description : Why is an organic compound fused with Sodium for testing nitrogen,halogens and sulphur ?
Last Answer : On fusing with sodium metal the elements presents in an organic compounds are converted in to ionic compounds of sodium which are water soluble which can be filtered and detected by the respective tests.
Description : The element least likely to be found in an organic compound is (a) oxygen (b) sulfur (c) nitrogen (d) silicon
Last Answer : silicon
Description : The complex organic compounds that may have first evolved in the direction of origin of life on earth, may have been
Last Answer : The complex organic compounds that may have first evolved in the direction of origin of life on ... Proteins, nucleic-acid D. Protein, amino-acid
Description : Oral neomycin is beneficial in hepatic coma because: A. In hepatic failure patients it is absorbed from the intestines B. It decreases ammonia production by gut bacteria C. It reacts chemically with ... gut to prevent its diffusion into blood D. It induces ammonia detoxifying enzymes in the liver
Last Answer : B. It decreases ammonia production by gut bacteria
Description : The relation between molarity (M) and molarity (m) is given by : (`rho` = density of solution (g/mL), `M_(1)` = molecular weight of solute) :-
Last Answer : The relation between molarity (M) and molarity (m) is given by : (`rho` = density of solution (g/mL), `M_(1 ... ))` D. `m = (1000M)/(1000rho -MM_(1))`
Description : 1.250 g of metal carbonate `(MCO_(3))` was treated with 500 mL of 0.1 M HCl solution. The unreacted HCl required 50.0 mL of 0.500 M NaOH solution for
Last Answer : 1.250 g of metal carbonate `(MCO_(3))` was treated with 500 mL of 0.1 M HCl solution. The unreacted HCl ... the metal M A. Mg B. Ca C. Sr D. Ba
Description : . The absorption factor is defined as (where, L = liquid flow rate, G = gas flow rate and, m = slope of the equilibrium line). (A) L/mG (B) G/mL (C) mL/G (D) LG/m
Last Answer : (A) L/mG
Description : The chief source for the production of nitrogeneous fertilizers is : (1) Ammonia (2) Nitric acid (3) Nitrogen (4) Nitrogen dioxide
Last Answer : (1) Ammonia Explanation: Nitrogen fertilizers are often made using the Haber-Bosch process which uses natural gas for the hydrogen and nitrogen gas from the air at an elevated temperature and ... is used as a feedstock for other nitrogen fertilizers, such as anhydrous ammonium nitrate and urea.
Description : During nitric acid manufacture, catalytic oxidation of ammonia at 800°C in presence of platinum catalyst produces nitrogen oxide. Conversion of NH3 to NO is about __________ percent. (A) 38 (B) 68 (C) 82 (D) 98
Last Answer : (D) 98
Description : Which of the process is known as nitrification? (1) Reaction of Nitrogen Monoxide with oxygen to form nitric acid (2) Reaction of nitrogen dioxide with water to form nitric acid (3) Conversion of ammonia to nitrites (4) Conversion of nitrite to nitric oxide
Last Answer : Conversion of ammonia to nitrites
Last Answer : Ammonia
Description : 15 mL of water and 10 mL of sulphuric acid are to be mixed in a beaker (i) State the method that should be followed with reason. (ii)What is this process called? -Chemistry
Last Answer : (i) The acid is to be added slowly in water to prevent the mixture to be splashed. The reaction is highly exothermic, therefore, constant cooling should be done. (ii)The process is called dilution.
Description : 44 g of a sample of organic compound on complet combustion gives 88 g `CO_(2)` and 36 g of `H_(2)O` . The molecular formula of the compound may be :-
Last Answer : 44 g of a sample of organic compound on complet combustion gives 88 g `CO_(2)` and 36 g of `H_(2)O` . The ... . `C_(2)H_(4)O` D. `C_(3)H_(6)O`
Description : An organic compound ("X") is a disubstituted benzene containing 77.8% carbon and 7.4 % hydrogen. Heating an alkaline solution of "X" with chloroform g
Last Answer : An organic compound ("X") is a disubstituted benzene containing 77.8% carbon and 7.4 % hydrogen. Heating an alkaline ... "Z". "Z" is A. B. C. D.
Description : A piece of magnesium ribbon was heated to redness in an atmosphere of nitrogen and then cooled with water. The gas evolved is
Last Answer : A piece of magnesium ribbon was heated to redness in an atmosphere of nitrogen and then cooled with ... . ammonia B. hydrogen C. nitrogen D. oxygen
Description : During photosynthesis in plants, the gas evolved is - (1) Carbon dioxide (2) Nitrogen (3) Oxygen (4) Hydrogen
Last Answer : (3) Oxygen Explanation: Photosynthesis is a process used by plants and other organisms to convert the light energy captured from the sun into chemical energy that can be used to fuel the organism ... , through primary production, or indirectly, as the ultimate source of the energy in their food.
Description : During photosynthesis in plants, the gas evolved is (1) Carbon dioxide (2) Nitrogen (3) Oxygen (4) Hydrogen
Last Answer : Oxygen
Description : 25 mL of household bleach solution was mixed with 30 mL of o.50 M Kl and 10 mL of 4N acetic acid. In the titration of the liberated iodine, 48 mL of 0
Last Answer : 25 mL of household bleach solution was mixed with 30 mL of o.50 M Kl and 10 mL of 4N acetic acid. In the titration ... B. 0.96 M C. 0.24 M D. 0.024 M
Description : 4-amino-3-methylbutanoic acid is treated with thionyl chloride followed by ammonia to obtain compound X. X on reaction with, bromine in an alkaline me
Last Answer : 4-amino-3-methylbutanoic acid is treated with thionyl chloride followed by ammonia to obtain compound X. X on ... B. 80 mL C. 120 mL D. 200 mL
Description : Which of the following is NOT a nitrogenous waste compound excreted by animals? a) urea b) ammonia c) uric acid d) pyridine
Last Answer : ANSWER: D -- PYRIDINE
Description : In organic compounds, nitrogen is estimated by – (1) Carius method (2) Victor-Meyees method (3) Liebigs method (4) Dumas' method
Last Answer : (4) Dumas' method Explanation: In Dumas' method, a known quantity of nitrogen containing organic compound is heated strongly with excess of copper oxide in an atmosphere of carbon dioxide to produce free nitrogen in addition to carbon dioxide and water.
Description : In organic compounds, nitrogen is estimates by - (1) Dumas method (2) Carius method (3) Victor-meyer's method (4) Liebig's method
Last Answer : (1) Dumas method
Description : In organic compounds, nitrogen is estimated by (1) Carius method (2) Victor-Meyer’s method (3) Liebig’s method (4) Dumas’ method
Last Answer : Dumas’ method