Chemistry Questions and Answers August 24, 2020

Keeping the medulung constant same. The simplest ratio of coulombic energy of NaCl MgSO is x y. Then calculate the value of x y

An fcc lattice has lattice parameter a 400 pm. Calculate the molar volume of lattice (in ml) including all empty space (write answer upto 1 decimal place)

The density of solid argon is 1.65 g mL at 233C. If the argon atom is assumed to be sphere of radius 1.54 x 10 cm, what percentage of solid argon is empty space (Atomic weight of Ar 40 u.)

For a crystal the lattice parameter were found to be a0.82 nm, b 0.94 nm and c 0.75 nm. The value of d23 is 0.21 nm. Then the value of d, will be 399 nm. (Write answer upto 2 decimal place)

In the given carbon skeleton structure below. identify the carbon atom(s) with sp3 hybradization.

H

2. Write the balanced half reactions, and cell reaction for the cell schematic below, calculate the standard cell potential, and note whether the reaction is spontaneous under standard state conditions. Cu(s) Cu (aq) Au(aq) Au(s)

calculate an approximate enthalpy (in kJ) for the reaction of 5.28 g gaseous methanol (CH3OH) in excess molecular oxygen to form gaseous carbon dioxide and gaseous water by Using Table 9.4, . (Hint, remember to first write the balanced equation.) TABLE 9.4 Bond Energies (kJmol) Single Bonds CH 414 CC 348 CN 293 C0 351 CF 439. CC 328 CBr 276 C1 288

Name the following and state the number of hydrogens in each molecule 11) 14) HNCH CH 13) utst NH 16) 15) ja j OH 17) 12) NH 18) guit zel nh OH 19)

HELP When the nuclide thorium234 undergoes beta decay The name of the product nuclide is The symbol for the product nuclide is Submit Answer Retry Entire Group 9 more group attempts remaining

Propose possible reagent(s) of the following sequences of reactions. Remember to include solvents and conditions where appropriate. If more than one reagent is needed for a given transformation, number the steps. H. IV. AL

Propose possible reagent(s) of the following sequences of reactions. Remember to include solvents and conditions where appropriate. If more than one reagent is needed for a given transformation, number the steps. H. IV. AL

The compound that does not liberate CO2, on treatment with aqueous sodium bicarbonate solution, is: (a) Benzoic acid (b) Benzenesulfonic acid (c) Salicylic acid (d) Carbolic acid (phenol)

The correct acidity order of the following is; (a) III>IV>II>I (b) IV>III>I>II (c) III>II>I>IV (d) II>III>IV>I

OH (I) C1 (II) COOH () COOH CH3 (IV)

The correct stability order of the following resonance structures is (a) (I) > (II) > (IV) > (III) (b) (I) > (III) > (II) > (IV) (c) (II) > (I) > (III) > (IV) (d) (III) > (I) > (IV) > (II)

HCNN (1) HCNN (III) HCNN (II) HCNN (IV)

Amongst the following, the total number of compounds soluble in aqueous NaOH is: (a) 3 (b) 5 (c) 2 (d) 4

H3C N CH3 CHCH3 COOH NO CHOH OH o OH H3CN CH3 CHCH3 CHCH3 COOH

Which among the following compounds is the most acidic. (a) p-nitrophenol (b) p-hydroxybenzoic acid (c) o-hydroxybenzoic acid (d) p-toluic acid

The carboxyl functional group (COOH) is present in (a) Picric acid (b) Ascorbic (c) Barbituric acid (d) Aspirin

Which of the following molecules in pure form is (are) unstable at room temperature

066 C. A. B. D.

The most basic compound among the following is (a) Acetanilide (b) Benzylamine (c) p-Nitro aniline (d) Aniline

Due to the presence of an unpaired electron, free radicals are (a) Chemically reactive (b) Chemically inactive (c) Anions (d) Cations

Mixture(s) showing positive deviation from Raoults law at 35 o C is/are. (A) Carbon tetrachloride + methanol (B) Carbon disulphide + acetone (C) Benzene + toluene (D) Phenol + aniline

The molar volume of liquid benzene (density = 0.877g/ml -1 ) increases by a factor of 2750 as it vaporises at 20C and that of liquid toluene (density = 0.867g mL -1 ) increases by a factor of 7720 at 20C. A solution of benzene and toluene at 20C has a vapour pressure of 46.0 torr. Find the mole fraction of benzene in the vapour above the solution.

The mole fraction of urea in an aqueous urea solution containing 900 g of water is 0.05. If the density of the solution is 1.2 g cm -3 , the molarity of urea solution is ________. (Given data: Molar masses of urea and water are 60 g mol1 and 18 g mol1, respectively)

A crystalline solid of a pure substance has a face-centred cubic structure with a cell edge of 400pm. If the density of the substance in the crystal is 8g cm -3 , then the number of atoms present in 256g of the crystal is N 10 24 . The value of N is.

Consider an ionic solid MX with NaCl structure. Construct a new structure(Z) whose unit cell is constructed from the unit cell of MX following the sequential instructions given. Neglect the charge balance. (i) Remove all the anions(X) except the central one. (ii) Replace all the face centred cations(M) by anions(X). (iii) Remove all the corner

What is the calculated value of the cell potential at 298 K for an electrochemical cell with the following reaction, when the F pressure is 1.12 atm, the F concentration is 1.66 x 10M, and the Hg2 concentration is 6.18 10 M F2(g) Hg(1)2F (aq) Hg (aq) Ecell The cell reaction as written above is spontaneous for the concentrations given true

Which type of defect has the presence of cations in the interstitial sites? (A) Vacancy defect (B) Frenkel defect (C) Metal deficiency defect (D) Schottky defect

When the Ag concentration is 1.66 x 104 M, the observed cell potential at 298 K for an electrochemical cell with the following reaction is 2.942V. What is the Mg2 concentration 2Ag (aq) Mg(s) 2Ag(s) Mg (aq) Mg M

The most recently produced synthetic elements have halflives of the order of Select one a. decades O b. hours O c. O d. e. centuries days seconds

If the halflife of a 4 gram sample of a radionuclide is 11 hours, then the halflife of a 2 gram sample of the same radionuclide would be Select one O a. 11 b. 5.5 C. 88 d. 44 O e. 22

Benzene and naphthalene form an ideal solution at room temperature. For this process,the true statement(s) is (are) (A) -Gsystem is positive (B) +S system is positive (C) Ssurroundings = 0 (D) H = 0

If the freezing point of a 0.01 molal aqueous solution of a cobalt(III) chloride-ammonia complex (which behaves as a strong electrolyte) is 0.0558C, the number of chloride(s) in the coordination sphere of the complex is. [Kf of water = 1.86 K kg mol -1 ]

MX 2 dissociates into M 2+ and X? ion in an aqueous solution, with a degree of dissociation (?) (?) of 0.5. The ratio of the observed depression of freezing point of the aqueous solution to the value of the depression of freezing point in absence of ionic dissociation.

On dissolving 0.5 g of non-volatile, non-ionic solute to 39 g of benzene, its vapour pressure decreases from 650 mm of Hg to 640 mm of Hg. The depression of the freezing point of benzene (in K) upon addition of the solute is ___. [Given data: Molar mass and molar freezing point depression of benzene is 78 g mol -1 and 5.12 K kg mol -1 ]

1)In a mortar, the binding material is? 2)Wrought iron contains carbon upto____? 3)Ultimate strength to cement is provided by_____? 4)Elastomers can extend upto_____? 5) In the cement the compound quickest to react with water, is

In a galvanic cell, the salt bridge: (A) Does not participate chemically in the cell reaction (B) Stops the diffusion of ions from one electrode to another (C) Is necessary for the occurrence of the cell reaction (D) Ensures mixing of the two electrolytic solutions

Consider a 70% efficient hydrogen-oxygen fuel cell working under standard conditions at 1 bar and 298 K. Its cell reaction is; H 2 (g) + O 2 (g) ? H 2 O(l) The work derived from the cell on the consumption of 1.0 10 -3 mol of H 2 (g) is used to compress 1.00 mol of a monoatomic ideal gas in a thermally insulated container. What is the change in

For the following cell, Zn(s) | ZnSO 4 (aq) || CuSO 4 (aq) | Cu(s) when the concentration of Zn 2+ is 10 times the concentration of Cu 2+ , the expression for ?G (in J mol1) is [F is Faraday constant; R is gas constant; T is temperature; E (cell) = 1.1V]. (A) 1.1F (B) 2.303RT 2.2F (C) 2.303RT + 1.1F (D) 2.2F

AgNO 3 (aq.) was added to an aqueous KCl solution gradually and the conductivity of the solution was measured. The plot of conductance (?) versus the volume of AgNO 3 is. (A) (P) (B) (Q) (C) (R) (D) (S)

A Volume (P) Volume (R) A Volume (Q) Volume (S)

Consider the following reversible reaction, A(g) + B(g) ? AB(g). The activation energy of the backward reaction exceeds that of the forward reaction by 2RT (in J mol -1 ). If the pre-exponential factor of the forward reaction is 4 times that of the reverse reaction, the absolute value of ?G? (in J mol -1 ) for the reaction at 300 K is____. Given;

The standard enthalpy of formation of NH 3 is 46 kJ mol 1 . If the enthalpy of formation of H 2 from its atoms is 436 kJ mol 1 and that of N 2 is 712 kJ mol 1 , the average bond enthalpy of NH bond in NH 3 is (A) 1102 kJ mol 1 (B) 964 kJ mol 1 (C) + 352 kJ mol 1 (D) + 1056 kJ mol 1

Identify the correct statement regarding a spontaneous process: (A) Lowering of energy in the reaction process is the only criterion for spontaneity. (B) For a spontaneous process in an isolated system, the change in entropy is positive. (C) Endothermic processes are never spontaneous. (D) Exothermic processes are always spontaneous.

The correct statement(s) pertaining to the adsorption of a gas on a solid surface is (are); (A) Adsorption is always exothermic (B)Physisorption may transform into chemisorption at high temperatures (C) Physisorption increases with increasing temperature but chemisorption decreases with increasing temperature (D) Chemisorption is more exothermic

Methylene blue from its aqueous solution is adsorbed on activated charcoal at 25 o C. For this process, the correct statement is: (A) The adsorption requires activation at 25 o C (B) The adsorption is accompanied by a decrease in enthalpy (C) Athe adsorption increases with increases in temperature (D) The adsorption is irreversible

Match the catalysts to the correct processes. Catalyst Process (A) TiCl 3 (i) Wacker process (B) PdCl 2 (ii) Ziegler- Natta polymerisation (C) CuCl 2 (iii) Contact process (D) V 2 O 5 (iv) Deacons process (A) (A) (iii), (B) (ii), (C) (iv), (D) (i) (B) (A) (ii), (B) (i), (C) (iv), (D) (iii) (C) (A) (ii), (B) (iii), (C) (iv), (D) (i) (D)

Rate of physisorption increases with: (A) Decrease in temperature (B) Increase in temperature (C) Decrease in pressure (D) Decrease in surface area

When O 2 is adsorbed on a metallic surface, electron transfer occurs from the metal to O 2 . The TRUE statement(s) regarding this adsorption is(are) (A) O2 is physisorbed (B) Heat is released (C)Occupancy of ?2p of O 2 is increased (D) Bond length of O 2 is increased

Among the following, the surfactant that will form micelles in aqueous solution at the lowest molar concentration at ambient conditions is: (A) CH 3 (CH 2 ) 15 N + (CH 3 ) 3 Br (B) CH3(CH 2 ) 11 OSO 3 Na + (C) CH3(CH 2 ) 6 COO Na + (D) CH3(CH 2 ) 11 N + (CH 3 ) 3 Br

The qualitative sketches I, II and III given below show the variation of surface tension with a molar concentration of three different aqueous solutions of KCl, CH 3 OH and CH 3 (CH 2 ) 11 1OSO 3 ? Na + at room temperature. The correct assignment of the sketches is: (A) I:KCl; II:CH 3 OH; III:CH 3 (CH 2 ) 11 OSO 3 ? Na + (B) I:CH 3 (CH 2 ) 11 OSO

Surface tension I Concentration Surface tension II Concentration Surface tension III Concentration

The correct statement(s) about surface properties is(are): (A) Adsorption is accompanied by a decrease in enthalpy and a decrease in entropy of the system (B) The critical temperatures of ethane and nitrogen are 563 K and 126 K, respectively. The adsorption of ethane will be more than that of nitrogen on the same amount of activated charcoal at a

Choose the correct reason(s) for the stability of the lyophobic colloidal particles. (A) Preferential adsorption of ions of their surface from the solution (B) Preferential adsorption of solvent on their surface from the solution (C) Attraction between different particles having opposite charges on their surface (D) Potential difference between

The given graph/data I, II, III and IV represent general trends observed for different physisorption and chemisorption processes under mild conditions of temperature and pressure. Which of the following choice(s) about I, II, III and IV is (are) correct? (A) I is physisorption and II is chemisorption (B) I is physisorption and III is chemisorption

(III) Amount of gas absorbed p constant T 200 K 250 K A (IV) Potential energy p constant T Eads Distance of molecule from the surface Ahads 150 kJ mol

For a reaction, A ? P, the plots of [A] and [P] with time at temperatures T1 and T2 are given below. If T 2 > T 1 , the correct statement(s) is (are) (Assume ?H ? and ?S ? are independent of temperature and ratio of lnK at T 1 to lnK at T 2 are greater than T 2 /T1 1 Here H, S, G and K are enthalpy, entropy, Gibbs energy and equilibrium

A(mol L 10 Time T 2 T 10 P(mol L) S Time T AA I

a bimolecular reaction, the steric factor P was experimentally determined to be 4.5. The correct option(s) among the following is(are) (A) The activation energy of the reaction is unaffected by the value of the steric factor (B) Experimentally determined value of frequency factor is higher than that predicted by Arrhenius equation (C) Since P =

According to the Arrhenius equation, (A) A high activation energy usually implies a fast reaction (B) Rate constant increases with an increase in temperature. This is due to a greater number of collisions whose energy exceeds the activation energy. (C) Higher the magnitude of activation energy, the stronger is the temperature dependence of the

ln a first-order reaction the concentration of reactant decreases from 800 mol/dm 3 to 50 mol/dm 3 is 2 10 4 sec. The rate constant of reaction in sec -1 is: (A) 2 10 4 (B) 3.45 10 -5 (C) 1.386 10 -4 (D) 2 10 -4

According to the graph, at 60 C, how much potassium amount can 100 g of water hold?

According to the graph, at 60 C, how much potassium amount can 100 g of water hold 240 220 200 180 160 Solubility 140 (g100 g of HO) 120 100 155 g 85 g 110 g 40 g 80 60 40 20 20 40 Nacloa KNO3 NaCl 60 80 Temperature (C) KBr 100 120 rw

Radiator antifreeze (ethylene glycol: shown in the diagram being poured into a vehicle radiator) is diluted with an appropriate quantity of water to prevent freezing of the mixture in the radiator. A 4.00 litre container of 94% antifreeze is diluted to 9.00 litres. The concentration of the final solution is

Radiator antifreeze (ethylene glycol shown in the diagram being poured into a vehicle radiator) is diluted with an appropriate quantity of water to prevent freezing of the mixture in the radiator. A 4.00 litre container of 94 antifreeze is diluted to 9.00 litres. The concentration of the final solution is 36 24 212 42 FUSE WNOCSI BEFORE

A chemical analysis requires exactly 10.00 mL of a sai be transferred to a volumetric flask. The most appropriate piece of glassware used to obtain this sample is a

A chemical analysis requires exactly 10.00 mL of a sai be transferred to a volumetric flask. The most appropriate piece of glassware used to obtain this sample is a pipet O graduated cylinder flask rw buret

The hydronium ion concentration of the original base solution used to collect the following data is During the titration of an unknown base solution with a perchloric acid solution, the following data were collected.

The hydronium ion concentration of the original base solution used to collect the following data is During the titration of an unknown base solution with a perchloric acid solution, the following data were collected. Volume of Acid Added (mL) 0.0 20.0 40.0 60.0 70.0 80.0 100.0 120.0 140.0 7.4 x 108 molL 1.0 x 1014 molL O 1.7 x 102 molL O 1.5 x

An aqueous solution is one in which * the solvent is water an electrolytic solution is formed dissociation has occurred a solute has dissolved

An aqueous solution is one in which the solvent is water an electrolytic solution is formed dissociation has occurred a solute has dissolved

What is the IUPAC name of the structure shown O7chloro3nonyne 3chloro6nonyne 6chloro3octyne 3chloro3nonyne

Microwave ovens emit microwave energy with a wavelength of 12.2 cm. What is the energy of exactly one photon of this microwave radiation E

What is the final concentration when 25.0 mL of a 12.0 M solution is diluted to 100.0 mL

magnesium copper(II) chloride O Mg(s) CuCl(aq) MgCl(aq) Cu(s) Mg(s) CuCl2(aq) MgCl(aq) Cu(s) O Mg(aq) CuCl2(s) MgCl2(s) Cu(aq) 2Mg(s) CuCl2(aq) 2MgCl(aq) Cu(s) O Mg(s) CuCl2(aq) No Reaction 4 pt

In which type of bond are electrons completely transferred from one atom to another, forming ions metallic covalent ionic hydrogen

What is the percent abundance of the size 4d nails in this sample Nail Size 4d 14d Number of Nails 123 77 Abundance Mass () (g) 3.65 11.95 Weighted Average (g) 6.8

A solution contains the label 0.8 M SO2. This means that there are 0.8 grams of SO2 in 1 liter of water. True or False

Which of the following actions would not cause a change in the molar solubility of the sparinglysoluble salt CaF 2 at equilibrium at 25 C Note that Ksp for Ca(OH)2 is 5.02x106 at 298 K. A. Increasing the pH of the solution B. Decreasing the pH of the solution C. Increasing the temperature to 125C D. Adding more CaF2(s) E. Adding some NaF(s)

Which of the following metals will dissolve in HNO3 but NOT in HCI Hint Table 20.1 may be useful. Click show instructions to reveal Table 20.1 Ag Au 5 pts Pb

Can someone explain to me the concept of what is occurring during a weak acid and strong base titration between unknown CH3COOH and NaOH in full detail am writing a lab report. It would be helpful to explain the purpose behind each of the calculations used to find the concentration of CH3COOH. The endpoint was reached at 24.3 ml by the way. Tools

The following pictures represent solutions of AgCl, which may also contain ions other than Ag and Cl which are not shown. Gray spheres represent Ag ions and dotted spheres represent Clions. (1) (1) If solution (1) is a saturated solution of AgCl, which of solutions (1)(4) represents the solution after a small amount of NH 3 is added and

Which of the following terms best describes the following pair of molecules,a) Isomers b) Geometrical isomers c) Configurational isomers d) Constitutional isomers

Which of the following alkanes has the ability to exhibit optical activity,a) Neopentane b) Isopentane c) 3Methylpentane d) 3Methylhexane

What is the molecular formula for the stereogenic centre alkane with the smallest molecular weight a) C7H16 b) C5H12 c) C6H14 d) C4H10

Which of the following statements regarding this compounds stereochemistry can be deduced,HO HO OH,a) This compound is optically active because the compound contains a centre, plane, or axis of chirality b) This compound is optically active because it has stereogenic centers that create cistrans isomers c) This compound is not optically active

There are three chiral centres in a molecule. In comparison to the original molecule, how many of this compound will have different boiling points stereoisomers (a) Seven (b) Two (c) One (d) Six

HC CH HC CH,The given molecules are (a) constitutional isomers (b) conformers (c) stereoisomers (d) identical (e) None of these

Explain the differences between cis and trans decalins stability and physical qualities.

Define Chiral catalyst. What is a Chiral reagent

The mass of 2 L carbon monoxide at STP A) 1.6 g B) 2.5 g C) 2.0 g D) 2.8 g

The volume occupied by one gram-equivalent of oxygen at 273 K and 550 mmHg is A) 7.74 L B) 5.6 L C) 6.84 L D) 6.08 L

21 mL of an acid can be neutralized by 7 mL of 0.3N alkali solution , what is the normality of acid? a) 0.3 N b) 0.2 N c) 0.1 N d) 0.6 N

if four alpha particles and two beta particles are emitted from uranium ( atomic number 92). What will be the atomic number of new element formed.? A) 100 B) 102 C) 98 D) 86

How many g/moles are present in 400 g of NaOH? A) 100 B) 50 C) 10 D) 40

How many grams of carbon are present in 528 g of carbon dioxide? a) 72 g b) 144 g c) 44 g d) 1936 g

An automobile tyre is inflated to pressure of 175KPa at 273K. By controlling the pressure at 250 Kpa, up to what temperature , the tyre can be heated? A) 390 K B) 350 K C) 400 K D) 375 K

1 g mole of a compoind consist of A) One molecule of the compound B) On atom of the compound C) 6.023*10^23 molecules D) 22.4*10^2 molecules

Compounds which have different arrangements of atoms in space while having same atoms bonded to each other are said to have a) position isomerism b) functional group isomerism c) chain isomerism d) stereoisomerism

Which of the following can make difference in optical isomers a) heat b) temperature c) polarized light d) pressure

3. Which of the following Fischer projections is different from the other three CH3 OH H HC Ph H,C. 3 H a) 1 b) 2 c) 3 d) 4 Ph 1 OH HO Ph CH3 2 OH Ph H

What is the relationship between the two groups in the following molecules a) They are equatorial to one another b) They are axial to one another c) They are cis to one another d) They are trans to one another

A radioactive isotope has half life period of 128.6 m, its decay constant is : A) 1/200 m-1 B) 1/300 m-1 C) 1/100 m-1 D) 1/50 m-1

An example of isoquinolin alkaloid is A) piperine B) coniine C) morphine D) quinine

Kiliani-Fischer synthesis is used for: A) Lengthening carbon chain B) Conversion of aldose to ketose C) Shortening of carbon atom chain D) Synthesis of ketoses

Pyridine reacts with a mixture of KNO3 and H2SO4 at 300 degree to form : A) 1-nitropyridine B) 2-nitropyridine C) 3-nitropyridine D) 4-nitropyridine

An amino acid containing sulphur group is: A) Glycine B) Alanine C) Cysteine D) Leucine

Which among the following is most basic? A) Benzylamine B) Aniline C) Acetanilide D) P-nitroaniline

What is the stereochemical relationship between the following two molecules H3CHC H3C a) Geometrical isomers b) Enantiomers c) Diastereomers d) Identical CH3 CHCH3

What is the molecular formula for the alkane of smallest molecular weight which possesses a stereogenic center a) C4H10 b) C5H2 c) C6H14 d) C7H16

Which of the following statements most accurately describes the stereochemistry between the various cyclohexanes a) Cis1,2dichlorocyclohexane and trans1,2dichlorocyclohexane rotate planepolarized light in opposite directions, and together in equal proportions form a racemic mixture b) The diaxial and diequatorial forms of trans1,3dichlorohexane