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 : Some amount of "20V" `H_(2)O_(2)` is mixed with excess of acidified solution of Kl. The iodine so liberated required 200 mL of 0.1 N `Na_(2)S_(2)O_(3)
Last Answer : Some amount of "20V" `H_(2)O_(2)` is mixed with excess of acidified solution of Kl. The iodine so liberated ... 56 mL B. 112 mL C. 168 mL D. 224 mL
Last Answer : Some amount of "20V" `H_(2)O_(2)` is mixed with excess of acidified solution of Kl. The iodine so liberated required ... . 0.8 g C. 4.2 g D. 0.98 g
Last Answer : Some amount of "20V" `H_(2)O_(2)` is mixed with excess of acidified solution of Kl. The iodine so liberated required ... 37.2 mL C. 5.6 mL D. 22.4 mL
Description : Oxidising product of substance `Na_(3)AsO_(3)` would be
Last Answer : Oxidising product of substance `Na_(3)AsO_(3)` would be A. `As_(2)O_(3)^(3-)` B. `AsO_(3)^(-3)` C. `AsO_(2)^(-4)` D. `AsO_(4)^(-3)`
Description : When sulphur is boiled with `Na_(2)SO_(3)` solution, the compound formed is
Last Answer : When sulphur is boiled with `Na_(2)SO_(3)` solution, the compound formed is A. ... sodium sulphate C. sodium persulphate D. sodium thiosulphate
Last Answer : When sulphur is boiled with `Na_(2)SO_(3)` solution, the compound formed is A. `Na_(2)SO_(4)` B. `Na_(2)S_(2) ... 2)S_(2)O_(6)` D. `Na_(2)S_(2)O_(3)`
Description : How many of the following compounds are possible products when chlorine is passed through hypo solution (i) S (ii) HCl (iii) `Na_(2)S` (iv) `Na_(2)SO_
Last Answer : How many of the following compounds are possible products when chlorine is passed through hypo solution (i) S (ii) ... )S_(4)O_(6)` (vi) `HClO_(4)`
Description : A solution containing `Na_(2)CO_(3)` and `NaOH` requires `300 ml` of `0.1 N HCl` using phenolphthalein as an indicator. Methyl orange is then added to
Last Answer : A solution containing `Na_(2)CO_(3)` and `NaOH` requires `300 ml` of `0.1 N HCl` using phenolphthalein ... solution is `(NaOH=40, Na_(2)CO_(3)=106)`
Description : A sol is prepared by addition to excess AgNO3 solution in KI solution. What charge is likely to develop on the colloidal particles ?
Last Answer : Ans. Positive.
Description : When sulphur is boiled is boiled with `Na_2 SO_3`, a compound `(X)` is produced, `(X)` with excess of `AgNO_3` solution gives a compound `(Y)` which i
Last Answer : When sulphur is boiled is boiled with `Na_2 SO_3`, a compound `(X)` is produced, `(X)` with excess of `AgNO_3` ... 2)SO_(5),Ag_(2)SO_(5),Ag_(2)SO_(4)`
Description : During the titration of a mixture of `Na_(2)CO_(3)` and `NaHCO_(3)` against HCl :
Last Answer : During the titration of a mixture of `Na_(2)CO_(3)` and `NaHCO_(3)` against HCl : A ... is used to detect the first and second end point
Description : `CH_(3)CH_(2)CH_(2)CONH_(2)` is boiled with aqueous NaOH, then the reaction mixture is acidified with HCl. The products obtained are
Last Answer : `CH_(3)CH_(2)CH_(2)CONH_(2)` is boiled with aqueous NaOH, then the reaction mixture is acidified with HCl. The ... CH_(3)CH_(2)CH_(2)COO^(-)+NH_(4)Cl`
Description : In the test for iodine, `I_(2)` is treated with sodium thiosulphate `(Na_(2)S_(2)O_(3))` : `Na_(2)S_(2)O_(3)+I_(2) to NaI +..`
Last Answer : In the test for iodine, `I_(2)` is treated with sodium thiosulphate `(Na_(2)S_(2)O_(3))` : `Na_(2)S_(2)O_(3 ... (4)` C. `Na_(2)S` D. `Na_(3)ISO_(4)`
Description : To a 25 mL `H_(2)O_(2)` solution excess acidified solution of Kl was added. The iodine liberated 20 ml of 0.3 N sodium thiosulphate solution. Use thes
Last Answer : To a 25 mL `H_(2)O_(2)` solution excess acidified solution of Kl was added. The iodine liberated 20 ml of ... strength of `H_(2)O_(2)` is 1.344 L
Description : When a strong beam of light is passed through a colloidal solution, the light will – (1) be scattered (2) pass unchanged (3) be absorbed (4) be reflected
Last Answer : (1) be scattered Explanation: When a strong beam of light is passed through a colloidal solution, the light will be scattered.
Description : When a strong beam of light is passed through a colloidal solution, the light will (1) be scattered (2) pass unchanged (3) be absorbed (4) be reflected
Last Answer : be scattered
Description : Why solid NaCl starts separating out from a saturated solution of NaCl if HCl gas is passed through it?
Last Answer : Ans. HCl in the solution provides Clions. This increases the ionic product in NaCl and so the solid NaCl starts separating out.
Description : The reagent used to test the presence of starch in leaves is – (1) Fehling's solution (2) Iodine solution (3) Million's reagent (4) Benedict's solution
Last Answer : (2) Iodine solution Explanation: The Iodine test is used to test for the presence of starch. Iodine solution — iodine dissolved in an aqueous solution of potassium iodide — reacts with the starch producing a purple black color.
Description : Iodine solution is used to test the presence of – (1) Sugar (2) Proteins (3) Starch (4) Fats
Last Answer : (3) Starch Explanation: Iodine solution is used to test the presence of starch.
Description : Iodine solution is used to test the presence of (1) Sugar (2) Proteins (3) Starch (4) Fats
Last Answer : Starch
Description : The reagent used to test the presence of starch in leaves is (1) Fehling’s solution (2) Iodine solution (3) Million’s reagent (4) Benedict’s solution
Last Answer : Iodine solution
Description : For the estimation of nitrogen, 1.4 g of an organic compound was digested by Kjeldahl method and the evolved ammonia acid absorbed in 60 mL of `M/10`
Last Answer : For the estimation of nitrogen, 1.4 g of an organic compound was digested by Kjeldahl method and the evolved ammonia ... ` B. `10%` C. `3%` D. `5%`
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 : `{:("Column" (I) , "Column"(II)), ((a) "Presence of halogen" , P. HNO_(3)//AgNO_(3)), ((b) "Presence of sulphur" , Q. Na_(2)[Fe(CN)_(5)NO]) , ((c) "Pr
Last Answer : `{:("Column" (I) , "Column"(II)), ((a) "Presence of halogen" , P. HNO_(3)//AgNO_(3)), ((b) "Presence ... (d) "Presence of" P "and" S , S. FeCl_(3)):}`
Description : For testing the presence of starch in leaves, a boiled leaf is used. Why? -Science-7
Last Answer : When we boil leaf in alcohol, chlorophyll dissolves in warm alcohol. The leaf thus loses its green pigment and becomes colourless. This helps to clearly see any colour change on addition of Iodine.
Description : concentrated sulphuric acid on reaction with NaCl, NaBr and Nal produces HCl, bromine and iodine respectively. What order of oxidising ability of halo
Last Answer : concentrated sulphuric acid on reaction with NaCl, NaBr and Nal produces HCl, bromine and iodine respectively. What ... gt l_(2) gt H_(2)SO_(4)`
Description : The oxidation number of arsenic atom in `H_(3)AsO_(4)` is :-
Last Answer : The oxidation number of arsenic atom in `H_(3)AsO_(4)` is :- A. `-1` B. `-3` C. `+3` D. `+5`
Description : The solubility of `Ba_(3)(AsO_(4))_(2)`(formula mass=690) is `6.9xx10^(-2)` g//100 mL. What is the `K_(sp)`?
Last Answer : The solubility of `Ba_(3)(AsO_(4))_(2)`(formula mass=690) is `6.9xx10^(-2)` g//100 mL. What is the `K_(sp ... )` C. `1.0xx10^(-15)` D. `6.0xx10^(-13)`
Description : How many compound(s) or iron (s) can be oxidised by `H_(2)O_(2)` among the following (i) `AsO_(3)^(2)` (ii) `SO_(4)^(2-)` (iii) `Fe_(2) (SO_(4))_(3)`
Last Answer : How many compound(s) or iron (s) can be oxidised by `H_(2)O_(2)` among the following (i) `AsO_(3)^(2)` (ii) ... ` (v) `H_(2)S` (vi) PbS (vii) `O_(3)`
Description : During conversion of ammonium carbamate into urea, presence of large excess of water (A) Increases the yield of urea (B) Adversely affects the yield of urea (C) Reduces the evaporator load by diluting the urea solution (D) Does not affect the yield of urea
Last Answer : (B) Adversely affects the yield of urea
Description : The number of grams of iodine absorbed by 100 g fat or oil
Last Answer : Ans. Iodine value/number
Description : When `O_(3)` is passed through an aqueous solution of KI, the pH of the resulting solution is
Last Answer : When `O_(3)` is passed through an aqueous solution of KI, the pH of the resulting solution is A. 7 B. `6.8` C. `2.8` D. 43752
Description : `O_(3)` with KI solution produces
Last Answer : `O_(3)` with KI solution produces A. `Cl_(2)` B. `I_(2)` C. HI D. `HIO_(3)`
Description : How many grams of KI are in 25.0ml of a 3.0 (mv) KI solution?
Last Answer : The solution contain 12,47 g KI.
Description : Iodobenzene can be prepared by (a) treating chlorobenzene with I2 using FeCl3 catalyst. (b) treating phenol with I2 in NaOH solution. (c) treating benzenediazonium chloride with KI (d) treating benzene with CH3I using AlCl3 catalyst
Last Answer : treating benzenediazonium chloride with KI
Description : Aqueous solution of `Na_(2)S_(2)O_(3)` on reaction with `CI_(2)`, gives
Last Answer : Aqueous solution of `Na_(2)S_(2)O_(3)` on reaction with `CI_(2)`, gives A. `Na_(2)S_(2)O_(6)` B. `NaHSO_(4)` C. `NaCl` D. `NaOH`
Description : When 25 g of `Na_(2)SO_(4)` is dissolved in `10^(3)` Kg of solution, its concentration will be
Last Answer : When 25 g of `Na_(2)SO_(4)` is dissolved in `10^(3)` Kg of solution, its concentration will be A. 2.5 ppm B. 25 ppm C. 250 ppm D. 100 ppm
Description : If 25mL of a `H_(2)SO_(4)` solution reacts completely with `1.06g` of pure `Na_(2)CO_(3)` , what is the normality of this acid sotution :
Last Answer : If 25mL of a `H_(2)SO_(4)` solution reacts completely with `1.06g` of pure `Na_(2)CO_(3)` , what is the normality of ... N B. 0.5 N C. 1.8 N D. 0.8 N
Description : How many millilitres of `0.1 NH_(2)SO_(4)` solution will be required for complete reaction with a solution containing 0.125 g of pure `Na_(2)CO_(3)`?
Last Answer : How many millilitres of `0.1 NH_(2)SO_(4)` solution will be required for complete reaction with a solution containing ... .6 mL C. 26.3 mL D. 32.6 mL
Description : `Na_(2)CO_(3),NaCl, NaNO_(2),Na_(2)SO_(3),NaBr,CH_(3)CO O Na` are separately treated with `AgNO_(3)` solution. In how many cases white precipitate is/
Last Answer : `Na_(2)CO_(3),NaCl, NaNO_(2),Na_(2)SO_(3),NaBr,CH_(3)CO O Na` are separately ... solution. In how many cases white precipitate is/are obtained.
Description : A colouless solution of a compound gives a precipitate with `AgNO_(3)` solution but no precipitate with a solution of `Na_(2)CO_(3)`. The action of co
Last Answer : A colouless solution of a compound gives a precipitate with `AgNO_(3)` solution but no precipitate with a solution ... `CaCl_(2)` C. `Nal` D. `NaBr`