Chemistry Questions and Answers August 25, 2020

The IUPAC nomenclature of an element with electronic configuration [Rn] 5f 14 6d 1 7s 2 is (A) Unnilbium (B) Unnilunium (C) Unnilquadium (D) Unniltrium

The photochemical smog does not generally contain : (A) NO (B) NO 2 (C) SO 2 (D) HCHO

During the denaturation of proteins, which of these structures will remain intact? (A) Primary (B) Secondary (C) Tertiary (D) Quaternary

Drugs used to bind to receptors, inhibiting its natural function and blocking a message are called: (A) Agonists (B) Antagonists (C) Allosterists (D) Anti histaminists

Given below are two statements: Statement I: On heating with KHSO 4 , glycerol is dehydrated and acrolein is formed. Statement II: Acrolein has fruity odour and can be used to test glycerols presence. Choose the correct option. (A) Both Statement I and Statement II are correct. (B) Both Statement I and Statement II are incorrect. (C) Statement I

Melamine polymer is formed by the condensation of :

(A) (B) (C) (D) HN HN. HN. NH NH NH NH NH NH NH NH HCHO HCHO HCHO HCHO

An organic compound ?A? on reaction with NH 3 followed by heating gives compound B. Which on further strong heating gives compound C(C 8 H 5 NO 2 ). Compound C on sequential reaction with ethanolic KOH, alkyl chloride and hydrolysis with alkali gives a primary amine. The compound A is :

(A) (C) CHO CHO COOH COOH (B) (D) CHO COOH CHO OH

Which one of the following reactions does not represent correct combination of substrateand product under the given conditions?

(A) (B) (C) (D) CN Cl H Pd.BaSO4 (i) DIBALH (ii) HO COCH5 (i) AlH(iso Bu)2 (ii) HO OH (1) NaCrO7 (ii) HSO4, HO H H H H

Most stable product of the following reaction is :

OH (i) HC (ii) NaCN, DMF SOCl, Pyridine

A compound?A? on reaction with ?X? and ?Y? produces the same major product but differentby product?a? and ?b?. Oxidation of?a? gives a substance produced by ants. ?X? and ?Y? respectively are (A) KMnO 4 /H + and dil. KMnO 4 , 273 K (B) KMnO 4 (dilute), 273 Kand KMnO 4 /H + (C) KMnO 4 /H + and O 3 , H 2 O/Zn (D) O 3 , H 2 O/Zn and KMnO 4 /H +

CH3 CH3 HCCCHCCH3 CH3 Compound A X Y CH3 CH3 aOCCH,CCH3 I CH3 CH3 CH3 b0CCHCCH3 I CH3

sodium salt when treated with MgCl 2 gives white precipitate only on heating. The anion is: (A) SO 4 2- (B) HCO 3 (C) CO 3 2- (D) NO 3

The species that do not contain peroxide ions, is (A) PbO2 (B) H 2 O 2 (C) SrO 2 (D) BaO 2

The correct opion(s) related to adsorption process is (are) (A) Chemisorption results in unimolecular layer. (B) The enthalpy change during physisorption is in the range of 100 to 140 kJ mol (C) Chemisorption is an endothermic process (D) Lowering the temperature favours physisorption process

The following compounds have been arranged in order of their increasing thermal stabilities. Identify the correct order. K 2 CO 3 (I), MgCO 3 (II), CaCO 3 (III), BeCO 3 (IV) (A) I < II < III < IV (B) IV < II < III < I (C) IV < II < I < III (D) II < IV < III < I

In Zeolites and synthetic resin method, which will be more efficient in removing permanent hardness of water. (A) Synthetic resin method as it exchanges only cation. (B) zeolite resin method as it exchanges only cation. (C) Synthetic resin method as it exchanges only anion. (D) Synthetic resin is harmful to nature.

Match the rate expressions in LISTI for the decomposition of X with the corresponding profiles provided in LISTII. X, and k are constants having appropriate units. LISTI (1) (II) (III) kx X X under all possible initial concentrations of X rate rate kX X X where initial concentrations of X are much less than X kX Xs X where initial

LISTI contains compounds and LISTII contains reactions. LISTI (1) HO (II) (III) (IV) Mg(OH)2 BaCl CaCO3 (P) (Q) (R) LISTII Mg(HCO3) Ca(OH) BaO,H,SO4 Ca(OH) MgCl BaO, HCI (T) Ca(HCO3)2 Ca(OH) Match each compound in LISTI with its formation reaction(s) in LISTII, and choose the correct option (A) I Q II P III S IV R (B) I T II P III Q IV

LISTI contains metal species and LISTII contains their properties. LIST I (P) (I) Cr(CN) (II) RUCI, (III) Cr(HO) (IV) Fe(HO) LISTII t2g orbitals contain 4 electrons (Q)(spinonly) 4.9BM Low spin complex ion Metal ion in 4 oxidation state d species (R) (S) (T) Given Atomic number of Cr 24, Ru 44, Fe 26 Match each metal species in LISTI with

Based on lattice energy and other considerations, which one of the following alkali metal chloride is expected to have the highest melting point ? (A) RbCl (B) LiCl (C) KCl (D) Nacl

Draw the Lewis dot structure for CH?O.

Determine the balanced equation for the precipitation reaction resulting from mixing the pairs of ionic compounds shown below a) Aqueous sodium carbonate reacts with aqueous copper(II) sulfate Enter your chemical notation here b) Aqueous copper(II) sulfate reacts with aqueous barium chloride Enter your chemical notation here

Rank the effective nuclear charge Z experienced by a valence electron in each of these atoms atom An atom of scandium. An atom of nickel. An atom of manganese. An atom of zinc. z experienced by a valence electron. (pick one) (pick one) (pick one) (pick one)

A Predict the missing component in the nuclear equation. 226 Ra X 230 Th 90 88 42 He S 87 e

Determine E, AG, and K for the overall reaction from the balanced halfreactions and their standard reduction potentials. 2 Co HAsO, HO 2 Co H,AsO 2H E AG Co HAsO 2H 2e Co H,AsO, HO V J E 1.92 V E 0.575 V K Is the overall reaction spontaneous as written not spontaneous spontaneous

Discuss how does dissolving a salt molecule in water make its atoms ionize?

How do plants get their nitrogen from the air?

When 0.25 g magnesium powder is taken into the calorimeter. Then pour 50 ml HCl into this calorimeter, its temperature increases from 24 C to 38 C. Assume the density of dilute or aqueous solution is 1.0 gml and specific heat is just like that of water 4.184 Jg.C. calculate molar enthalpy of this reaction

We are given hydrated copper sulphate CuSO4.x HO with mass 4.00 g. calculate the following. 1. Calculate the percentage composition of water by mass in this hydrate 2. Calculate the value of x and write the complete formula for the hydrate 3. The actual formula of the hydrate is CuSO4.5HO using the following equation, calculate error for your

How do I know if something is an acid so I can avoid eating it? Give detailed answer.

Explain why doesn't the planet Uranus explode if it contains so much hydrogen and methane? 30 marks.

1. Discuss why is mass conserved in chemical reactions? 2. Discuss why is plastic not used in home construction? Discuss each in detailed.

Discuss why is propane stored in household tanks but natural gas is not? 20 marks

What is the reason for the extra stability of half-filled and fully filled orbitals?

What are the conditions for the spontaneity of a process?

A solution of sodium chlorate (NaClO3) is a highly effective herbicide. Calculate the volume of 4.30 molL NaClO3(aq) required to make 50.0 mL of 3.75 molL solution

why glass is considered a pseudo-solid.

__________ are a class of chemical compounds used for the treatment of stress, and mild or even severe mental diseases. (A) Tranquilizers (B) Antiseptics (C) Analgesics (D) None of above

Which is used in cancer chemotherapy? (A) Cis-platin (B) Zeisse's salt (C) Both (a) and (b) (D) None of these

____ are proteins that are crucial to body's communication process. These are present in cell membranes but a small active part of it projects out of the membrane. (A) Lipids (B) Enzymes (C) Synapses (D) Receptors

It is safer to use soap compared to detergent from the environmental point of view. Reason Soaps are biodegradable, while detergents containing branched hydrocarbon chains are quite stable. Read the above assertion and reason and choose the correct option regarding it. (A) Both Assertion and Reason are correct and Reason is the correct explanation

Write a nuclear equation for the most likely mode of decay for each unstable nuclide a. Kr74 b. Th221 c. Ar44 d. Nb85

What is adsorption chromatography and partition chromatography?

What are the different types of chromatography and their uses with examples?

What is the importance of the RF value in chromatography?

Are thin layer chromatography and paper chromatography stationary phases the same?

Which are some of the things that necessitate the use of experimental kinetic data in unit processes?

When 3-ethylcyclohexanone is reacted with a base (eg KOH), what two products would you expect? Show the complete mechanism for obtaining one of the two products (choose either).

Write the complete mechanism for each of the following reactions (i) H3C CH,O CH3 CHCH3 (1) LDA (2) PhSeBr (3) HO, 25 C 2 CH3O HCH CH3 CHCH 6 marks

Write complete mechanism of the given reaction.

x CH3CHBr Wittig CHCH3

How do you achieve the following transformation? Give all reagents and intermediates.

H3C Eto OEt

How many moles of NaCl are produced from 15.5g of HCl, according to the neutralization reaction HCl(aq) NaOH(aq) NaCl(aq) HO(1)

What mass of aluminium oxide (AlO3) is produced from 14.5g of Al metal when it reacts completely with oxygen gas according to the following equation. 4Al(s) 302(g) 2Al2O3(s)

The percentage yield of the following reaction is 85 . 2Al(s) 3Cl2(g) 2AlCl3(s) How many grams of AlCl3 will be obtained from 100g of aluminium metal(Al).

A reaction has a theoretical yield of 45.8 g. When the reaction is carried out, 27.2 g of the product forms. What is the percent yield 81.2 59.4 35.1 168 44.8

What is the role of the phosphate buffer in the body?

What component of the phosphate buffer neutralizes the acidic products of metabolism? Write down a reaction between this component and HCI:

What is the role of carbonic acid - bicarbonate buffer?

What component of the carbonic acid - bicarbonate buffer neutralizes the basic products of metabolism?

Explain how electrical neutrality is maintained in compounds showing Frenkel and Schottky defect.

Calculate the number of atoms in a cubic unit cell having one atom on each corner and two atoms on each body diagonal.

The electrical conductivity of a metal decreases with rise in temperature while that of a semi-conductor increases.Explain.

What type of substances would make better permanent magnets, ferromagnetic or ferromagnetic,Why?

In a crystalline solid, the atoms A and B are arranged as follows: a. atoms A are arranged in ccp array b. atoms B occupy all the octahedral voids and half of the tetrahedral voids. What is the formula of the compound?

An element E crystallizes in body centered cubic structure. If the edge length of the cell is 1.49 X 100 m and the density is 19.3gcm, calculate the atomic mass of this element. Also calculate the radius of an atom of the element.

Analysis shows that a metal oxide has the empirical formula Mo.9601.00 Calculate the percentage of M and M ions in this crystal. OR i) What type of substances show antiferromagnetism ii) Assign reason for the fact that silicon doped with phosphorus is a semiconductor.

Calculate the density of silver which crystallizes in face centred cubic form. The distance between nearest metal atoms is 287pm.(molar mass of Ag=107.87gmol-1, No=6.022 x 1023)

Give an example of a miscible liquid pair showing positive deviation from the Raoults Law. Give reason.

Differentiate between molarity and molality of a solution. What is the effect of change in temperature on its molality and molarity values?

i) Why is an increase in temperature observed on mixing chloroform and acetone? ii) Why does sodium chloride solution freeze at a lower temperature than water?

A solution containing 15g of urea ( molar mass = 60 g mol-1 ) per litre of solution in water has the same osmotic pressure (isotonic) as a solution of glucose ( molar mass=180gmol-1 ) in water. Calculate the mass of glucose present in one litre of its solution.

15g of an unknown molecular substance was dissolved in 450g of water. The resulting solution freezes at 0.34C. What is the molar mass of the substance (K for water is 1.86 K Kg mol)

i) ii) Cu 2e Ag le. Cu E 0.34V Ag E 0.80V Construct a galvanic cell using the above data. For what concentration of Ag ions will the emf of the cell be zero at 25C, if the conc of Cu ions is 0.1 M log 3.9190.593.

Write electrode reactions taking place in a dry cell.

What is change in free energy for electrolytic cell Ans AG is positive (i) How much electricity is required in couloumb for the oxidation of 1 mole of HO to O ii) Calculate the emf of the cell CrCr (0.1M) Fe (0.01M)Fe Given that ECr Cr 0.75V EFeFe 0.45V

Write the average and instantaneous rate expressions of the following reaction 5Br(aq) BrO3(aq) 6H (aq) 3Br(aq) 3HO(1)

A chemical reaction 2A4B C in gas phase occurs in a closed vessel. The concentration of B is found to increase by 510 mol L1 in 10 seconds, Calculate (a) the rate of appearance of B (b) the rate of disappearance of A.

Consider the reaction 2A B C D Following result were obtained in experiments designed to study the rate of reaction Experiment Initial conc of A No. MolL 1 2 3 0.10 0.20 0.20 Initial conc of B Moll X 0.10 0.20 0.40 Initial rate of formation of D (Molmin) 1.5 X 103 3.0 x 10 6.0 x 10

The following data were obtained during the first order thermal decomposition of SOCl at a constant volume. CBSE DELHI 2014 SOCl (g) SO (g) Cl (g) Experiment No. Total Pressure atm 1. 0.5 2. 0.6 Calculate the rate of the reaction when total pressure is 0.65atm. TimeSec 0 100

Copper can be extracted by hydro metallurgy but not zinc . Explain

Explain the oxidizing property of KMnO4

The chemistry of the actinoid elements is not so smooth as that of the Lanthanoids. Justify this statement by giving some examples from the oxidation state of these elements.

Explain giving reasons: (i) Transition metals and many of their compounds show paramagnetic behaviour. (ii) The enthalpies of atomisation of the transition metals are high. (iii) The transition metals generally form coloured compounds. (iv) Transition metals and their many compounds act as good catalyst.

Coenzyme A is A) a form of cellular energy. B) an anabolic electron carrier. C) a catabolic electron carrier. D) an activated carrier of twocarbon fragments.

Write the structures of the major products of the following: (i) 3-methylphenol mononitration (ii) 3-methylphenol dinitration (iii) phenyl methanolate mononitration.

If the solubility product of CuS is 6 x 10 -16 , calculate the maximum molarity of CuS in aqueous solution.

Determine the molarity of pure water (d = 1 g ml-1).

You are given the following materials - Marble chips, Zinc granules and Dilute hydrochloric acid. Identify the type of reaction when marble chips and zinc granules are added separately to acid taken in two tubes. Write chemical equations in each case.

What is the mole fraction of ethylene glycol in a solution containing 20g by mass? (a) 0.022 (b) 0.054 (c) 0.068 (d) 0.090

Capacity decisions are usually one-time decisions; once they have been made, we know the limits of our operations. 1. True 2. False

The solubility of salt of a weak acid(AB) at pH 3 is Y 10-3 mol L-1. The value of Y is___. (Given that the value of solubility product of AB (Ksp) = 2 10-10 and the value of ionization constant of HB(Ka) = 1 10-8)

The initial rate of hydrolysis of methyl acetate (1M) by a weak acid (HA,1M) is 1/100th of that of a strong acid (HX,1M), at 25oC. The Ka(HA) is. (A)1 10-4 (B) 1 10-5 (C) 1 10-6 (D) 1 10-3

Aqueous solutions of HNO3, KOH, CH3COOH and CH3COONa of identical concentrations are provided. The pair(s) of solutions which form a buffer upon mixing is (are) (A) HNO3 and CH3COOH (B) KOH and CH3COONa (C) HNO3 and CH3COONa (D) CH3COOH and CH3COONa

Dilution processes of a different aqueous solution, with water, are given in LIST-I. The effects of dilution of the solutions on [H+] are given in LIST-II. (Note: Degree of dissociation (?) of a weak acid and a weak base is

The incorrect statement among the following for this reaction is: (A) Decrease in the total pressure will result in the formation of more moles of gaseous X (B) At the start of the reaction, dissociation of gaseous X2 takes place spontaneously (C) ?equilibrium = 0.7 (D) KC < 7

When 100 mL of 1.0 M HCl was mixed with 100 mL of 1.0 M NaOH in an insulated beaker at constant pressure, a temperature increase of 0.7oC was measured for the beaker and its contents (Expt. 1). Because the enthalpy of neutralization of a strong acid with a strong base is a constant (-57.0 kJ mol-1), the experiment could be used to measure the

The % yield of ammonia as a function of time in the reaction: N 2 (g) + 3H 2 (g) ? 2NH 3 (g), ?H 1) is given below. If this reaction is conducted at (P, T 2 ), with T2 > T1, the %yield of ammonia as a function of time is represented by:

yield Time T

The thermal dissociation of equilibrium of CaCO3 (s) is studied under different conditions: CaCO3(g) ? CaCO(g) + CO2(g) For this equilibrium, the correct statement(s) is/are (A) ? H is dependent on T (B) K is independent of the initial amount of CaCO3 (C) K is dependent on the pressure of CO2 at a given T (D) ? H is independent of the catalyst, if

Solubility product constant (Ksp) of salts of type MX, MX2 and M3X at temperature T are 4.0 x 10-8, 3.2 x 10-14 and 2.7 x 10-15, respectively. Solubilities (mol, dm) of the salt at temperature T are in the order (A) MX > MX2 > M3X (B) M3X > MX2 > MX (C) MX2 > M3X > MX (D) MX > M3X > MX2

one liter saturated solution of AgCl [Ksp = 1.6 x 10-10], 0.1 mol of CuCl [Ksp = 1.0 x 10-10 ] is added. The resultant concentration of Ag+ in the solution is 1.6 10-x. The value of x is ___.

Each question contains STATEMENT-1 (Assertion) and STATEMENT-2 (Reason). Examine the statement carefully and mark the correct answer according to the instructions given below: Statement 1: For every chemical reaction at equilibrium, the standard Gibbs energy of the reaction is zero. Statement 2: At constant temperature and pressure, chemical