General Questions and Answers

Which of the following is not an example of combination reactic a 2H g O g 2H O 1 b AgNO3 aq NaCl aq c C s O g CO g d CH4 g 20 g AgCl s NaNO aq CO g 2H O g

Various binders were investigated for the preparation of an analgesic drug tablet The disintegration of 19 Marks tablet was measured in a physiological buffer and the disintegration times are tabulated below From the information provided identify the binder that you would expect to generate the lowest spreading co efficient value of the buffer on the tablet Explain your answer Binder Povidone Gelatin Disintegration time min 17 0 23 5

which of the following is not the evidence fo r presence of aldehyhyde a Reaction of glucose with hydrooxxylamin e b Reaction of glucose with br2 c Reaction of glucose HCN

0 224 litre Os gas at 1 atm 273K expanded adiabatic reversibly upto 8 times of its intial volume then magnitude of work done in process will be in cal vibrational modes of energy are inactive Give your answer as nearest integer

2 A sample of O is collected over water at 22 C and 748 torr pressure The volume of the gas collected is 82 0 cm How many grams of oxygen are present in the gas Vapour pressure of water at 22 C is 19 8 torr

You want to compare brands of paper towels to see which holds the most liquid Independent Variable Dependent Variable You want to know whether caffeine affects your appetite Independent Variable

b H C CH CoCl H N CC NH H O H C CH COC H N CH CH NH HO ii For each of the pairs of reactions below answer the following questions I What type of substitution reactions are they II Which mechanism are the data consistent with dissociative or associative mechanism Explain Fe H O H O Fe H O H 0 iii trans Co NH Br en HO trans CoBr en k 3 2 x 10 k 5 4 x 106 s k 6 0 x 10 s H O k 3 2 x 10 s k 1 2 x 10 sl k 1 4 x 10 H C CH CoCI H O H N C C NH CT H C CH CoCI H O H N CH CH NH CF Fe H O H 70 H O Fe H O H 70 H O trans Co NH H OKen B trans CoBr H O en Br

nsider a 100 gm oleum sample which is labelled as 110 H SO4 After adding only sufficient amount of water that can react only with 3 If x grams of pure H SO4 can be obtained from the solution Then the value of x 100 is 2

PIA D A C In above diagram A has five valence electrons and B C and D have six valence electrons each According to the L D S A has x formal charge B has y and C has z formal charge The above mentioned compound ion follows Lewis octet theory Give the answer of following question if A B C D belongs to p block Identify the formal charge of A B and C respectively

An equilibrium PC g PCI g Cl g is maintained at given temperature in a cylindrical system with movable piston The concentration PCI 5 PCI3 and Cl are found to be 0 01 0 4 and 0 4 mol L respectively In this system 4 moles of Cl 8 moles of PC are added and 0 2 moles of PCI3 removed which changes the volume by x times What will be value of equilibrium constant at new condition

Solutions 109 1 kg of an aqueous solution of sucrose is cooled and maintained at 4 C How much ice will be separated out if the molality of the solution is 0 75 K H O 1 86 kg mot K Since molality of solution is 75

In all other cases For Example If first third and fourth are the ONLY three correct options for a question with second option being an incorrect option selecting only all the three correct options will result the three correct options e g the first and fourth options without selecting any incorrect option second option in this case will result in 2 marks Selecting only one of the three cora fourth option without selecting any incorrect option second option in this case will result in 1 marks Selecting any incorrect option s second option in this case with or without sele result in 2 marks A gas mixture contains 1 mol CH and 2 mol SO3 correct statements are 0 Average molar mass of the mixture is 176 6 change in average molar mass of the mixture if SO3 is completely dissociated in SO and O 25 Mass ratio of CH and SO3 Initially present in the mixture is 1 10 If 1 mol more CH is added in the given gaseous mixture then new molar mass of the mixture is 48

i Explain the formation of peaks at 128 100 86 71 57 and 43 in the El mass spectrum of 4 octanone ii What is meant by DEPT and what are its applications iii Explain how simplification of complex proton NMR spectra can be done by increasing field strength and lanthanide shift reagents

If the oxidation state of the central atom is in an intermediate value it will act as 1 Oxidising agent only 2 Reducing agent only 3 Both oxidant and reductant 4 Cannot be predicted 0 1 O 2

Which of the following is not concerned to effective nuclear charge X 1 Higher ionization potential of carbon than boron 2 Higher ionization potential of magnesium than Aluminium 3 Higher values of successive ionization energy 4 Higher electronegativity of higher oxidation state

The enthalpy of formation of ethane ethylene and benzene from the gaseous atoms are 2839 2 2275 2 and 5506 kJmol respectively Calculate the resonance energy of benzene The bond enthalpy of C H bond is given as equal to 410 87 kJ mol A 80 68 kJ mol B 23 68 kJ mol C 96 68 kJ mol D 46 68 kJ mol

Match the oxide given in Column A with its chemical nature given in Column B Column A a NO b AS203 c SO3 d Na O Column B i Acidic ii Basic iii Neutral iv Amphoteric

The gas phase reaction 2 A B C is biomolecular with an activation energy of 24 000 cal mol The molecular weight and diameter of A are respectively 60 and 35 A Calculate from kinetic theory the specific rate constant for decomposition at 27 C

Estimate the mass of water that must evaporate from the skin to cool the body by 0 55 C Assume a body mass of 100 kg and assume that the specific heat capacity of the body is 4 0 J g C Express your answer using two significant figures VAXO 1500

570 g of potassium thiosulphate K S O3 reacts with copper sulphate to form cupric thiosulphate which is reduced by remaining potassium thiosulphate to give cuprous compound which reacts with the remaining potassium thiosulphate to form a complex compound potassium cuprothiosulphate K Cu S 03 GUSO K S O CuS 0 K SO4 2CuS O3 K S O3 Cu S O3 K S406 3C0 S 0 2K S O3 KlCue S 03 5 potassium cuprothiosulphate In this process 02 mole of potassium cuprothiosulphate is formed O 16 K 39 S 32 If instead of given amount of potassium thiosulphate 2 moles of potassium thiosulphate along with 3 moles of CUSO were taken initially then moles of potassium cuprothiosulphate formed a

16 Chlorophyll the green pigment in plants has the molecular formula C55H72MgN4O5 If 0 012 g of Mg is available to a plant for chlorophyll synthesis how many grams of carbon will be required to completely use up the magnesium C 12 H 1 Mg 12 N 14 O 16 1 0 33 g 2 0 66 g 4 1 35 g 3 0 99 a

One mole of Na2SO4 10H 0 is dissolved in 820 grams of water to make a solution What is the molality of Na ions in the resulting solution Atomic mass u H 1 0 16 Na 23 S 32 Only One Correct Answer A More than 2 molal B C Equal to 2 molal Less than 2 molal i

4 Na SO is added in water to make 12 w w solution having density 1 2 g mL Correct statement for resulting solution is are a Nearly 0 96 mole of Na SO4 dissolved per kg of H O b Normality of Na ion is equals to normality of so ion c Molarity of solution is less than molality 1 a b 2 b only 3 c only 4 a only

Two rods A and B of same cross sectional area A and length t connected in series between a source T 100 C and a sink T 0 C as shown in figure The rod is laterally insulated B K If TA and Te are the temperature drop across the rod A and B then TA 1 3 TB T T 100 C A 3K f f T 0 C B

570 g of potassium thiosulphate K SO reacts with copper sulphate to form cupric thiosulphate which is reduced by remaining potassium thiosulphate to give cuprous compound which reacts with the remaining potassium thiosulphate to form a complex compound potassium cuprothiosulphate K Cus S 03 s GuSO4 K S O CuS O3 K SO 2CuS O3 K S O3 Cu S O3 K SO 30u S O3 2K S O3 KalCus S 03 s potassium cuprothiosulphate In this process 0 2 mole of potassium cuprothiosulphate is formed O 16 K 39 S 32 Total moles of potassium thiosulphate reacted in the reactions is

An electric current is passed through two electrolytic cells connected in series one containing AgNO3 aq and other H SO4 ag WH volume of O measured at STP would be liberated from H SO4 if 1 mole of Ag are deposited from AgNO3 solution A 5 6 L B 2 8 L c 11 2 L 22 4 L

P 1 The enthalpy of reaction is maximum in which of the following reaction 1 NaOH HCl NaCl H O 2 NaOH HF NaF H O 3 NaOH HBr NaBr H O 4 All have same value In case of electronegativity will be high a enthalpy of react

If energy required to dissociate 16 g of gaseo hydrogen into free atoms is 3488 kJ at 25 C th the bond energy of H H bond will be NCERT Pg 17 1 384 kJ mol 3 384 1 mol 2 436 kJ mol 4 436 J mol

What volume in milliliters of H g at STP will be produced from the reaction of 50 0 mL of 12 0 M HNO3 with excess tin according to the following equation Sn s 2HNO3 aq Sn NO3 2 aq H2 g 1 34 x 10 mL 6 72 x 10 mL none of these 13 4 mL 6 72 mL

hydrogen 4 20 litres ammonia 25 litres nitrogen 15 litres hydrogen tres 50 If the weight oxygen the e 42 The maximum number of molecules is present in 1 15 L of water at STP 2 15 L of H O gas at STP 3 15 g of ice 4 Same in all 43 Concentrated aqueous sulphuric acid is 98 H SO4 w v and has a density of 1 80 gmL Molarity of solution 8x y 1 E 3 E 1 2 8 51 The numbe 1 8 3 7 52 Mole frac NaOH is

ect the correct statement s All electromagnetic radiation travel with speed of light in vacuum O Energy of photon of UV light is lower than that of yellow light Atomic spectrum is discontinuous spectrum The total energy of an electron in H like atom is greater than zero

Question 40 The specific conductivity of sparingly soluble salt AB ag at 298 K is 1 26 x 106 S cm and molar conductivity of Aa and Baq at infinite dilution are 62 Scm mol and 64 Scm mol respectively Solubility product Kp of salt AB is A 10 5 B 108 c 10 10 OD 10 16

Carbon forms two oxides namely carbon monoxide and carbon dioxide The equivalent mass of which element remains constant b of a Carbon b oxygen d neither carbon nor oxygen c both carbon and oxygen

In permanganate titrations potassium permanganate is used as an oxidizing agent in acidic medium The medium is maintained acidic by the use of dilute sulphuric acid Potassium permanganate acts as self indicator The potential equation when potassium permanganate acts as an oxidizing agent is 2KMnO4 3H SO4 K SO4 2MnSO4 3H O 5 0 or MnO4 8H 5e Mn 4H O Before the end point the solution remains colourless but after the equivalence point only one extra drop of KMnO4 solution imparts pink colour i e appearance of pink colour indicates end point These titrations are used for estimation of ferrous salts oxalic acid oxalates hydrogen peroxide As O3 etc For decolourization of 1 mol of KMnO4 the number of moles of H C O4 required is

10 If 1 mol of an ideal gas at constant temperature changes its pressure from 5 atm to 2 atm and volume from 4 L to 10 L then enthalpy change wi be NCERT Pg 167 1 20 L atm 3 Zero 2 120 L atm 4 100 tm

B D A C In above diagram A has five valence electrons and B C and D have six valence electrons each According to the L D S A has x formal charge B has y and C has z formal cha follows Lewis octet theory Give the answer of following question if A B C D belongs to p block

Which of the following statement is not true 1 K Cr O solution in acidic medium is orange 2 K Cr O solution becomes yellow on increasing the pH beyond 7 3 On passing H S through acidified K Cr O solution a milky colour is observed 0 4 The bond angle of Cr O Cr 0 Cr O in

If AB is incident wavefront Then refracted wavefront just after transmission is A B A B B A A Biconvex lens

The Windscale fire is an accident that happened in October 1957 in the U K and has a level 5 severity from the INES scale The accident released radioactive fallout from iodine 131 polonium 210 and possibly strontium 90 What amount of each of the given radioisotopes would have registered a radioactivity of 25 000 Ci Isotope 210Po HA Sr 38 Atomic Mass u 130 9061246 209 9828737 89 907738 Half Life 8 02070 days 138 376 days 28 90 years

Copper is a transition metal that forms different coloured complexes A complex Cu H O 5 aq changes colour when excess Cl aq is added Explain the cause of this colour change using section 3 and 15 from the data booklet

A polyhydric alcohol X whenever treated with excess of propanoyl chloride then organic compound Y is obtained if difference in molecular mass of X Y is 280 then no of OH groups in X are The alcohol among following which show dehydration reaction faster than 2 methyl propan 2 ol OH

Two 22 4 litre containers A and B contains 8 g of O and 8 g of SO respect and 1 atm pressure then a Number of molecules in A and B are same 25 I b Number of molecules in B is more than that in A c The ratio between the number of molecules in A to number of molecules in BRG 2 1 27 d Number of molecules in B is three times greater than the number of molecule in A 1 pisegater the

A state of equilibrium is reached when 1 The rate of forward reaction is greater than the rate of the reverse reaction 2 The concentration of the products and reactants are equal 3 More product is present than reactant 4 The concentration of the products and reactants have reached constant value

3 PCI g PC1 g Cl g 4 14 Heat of combustion of CH4 C H4 and C H are 890 1411 and 1560 kJ mol respectively Which has the lowe calorific fuel value in kJ g 1 CH 3 C H Not sign only magnitud wise 2 C H4 4 All of these 13 7 94 11 2 and 12 4 kcal respectively w

At 17 C the osmotic pressure of sugar solution is 580 torr The solution is diluted and the temperature is raised to 57 C The osmotic pressure is found to be 165 torr The extent of dilution is Only One Correct Answer A 2 times B C D 4 times 6 times A times 0 Marked for Re o Answered and 7 Completed 16 21 CHEMISTR 26 17 22 27

The most probable molecular energy kT at 27 C is kT 2 52x10 2eV to What fraction of the potassium fluoride ion pairs have enough kinetic energy dissociate in the gas phase What fraction of the potassium fluoride ion pairs have enough kinetic energy to dissociate in the aqueous solution

CH CH CH A CH CH CH Br B CH CHBr CH CCH CHBr CH Br DBACH CH CH ii HBr peroxide iv Br CCl4 b C d A 0 0 iv mm B 0 0 iv C 1 i iv 1 D mm iv List 11 1 HBr i NBS

The oxidation of o dianisidine o DIA is electrochemically reversible and involves the transfer of two electrons Linear swee voltammetry was performed on a 2 M H SO solution containing 2 66 mM of o DIA using a carbon paste electrode with an of 3 36 mm At a scan rate of 500 0 mV s the peak current was 8 80 A Determine the diffusion coefficient D for o DIA D 035 10 6 Incorrect Determine the peak current if the scan rate is reduced to 225 0 mV s

A B ve N2 g 3H2 g 2NH3 g AH N2 g O2 g 2NO g AH ve C A g B g 2C g D g AH ve D PC15 g PCl3 g Cl2 g AH ve m P S List 11 K increases with increase in temperature K decreases with increase in temperature Pressure has no effect Moles of product increase due to addition of inert gas at constant pressure

A closed vessel contains a mixture of two diatomic gases A and B Molar mass of A is 16 times that of B and mass of gas A contained in the vessel is 2 times that of B Average kinetic energy per molecule of gas A is equal to that of gas B Root mean square value of translational velocity of gas B is four times that of A Pressure exerted by gas B is eight times of that exerted by gas A Number of molecules of gas B in the cylinder is eight times that of gas A