DELHI PUBLC SCHOOL.DHALIGAON
ASSIGMENT TARGET: 2016
CLASS: XII
P-BLOCK ELEMENTS
Q.1. Ammonia has higher boiling point than phosphine . Why?
Q. 2.Why does Pcl3 fume moisture?
Q .3. What happens when H3 PO3 is heated?
Q.4. Why H2S is acidic and H2O is neutral?
Q.5. Name two poisonous gases which can be prepared from Chlorine gas?
Q.6. Why is N2 less reactive at room temperature?
Q.7. what happens when white Phosphorus is heated with conc. Na OH solution in an
atmosphere of CO2?
Q8.Why is H2O is liquid and H2S a gas?
Q.9.Why does O3 acts a powerful oxidizing agent?
Q.10.Write the conditions to maximize yield of H2SO4 by contact process.
Q.11.Give the reasons for bleaching action of chlorine.
Q.12.Why is ICl more reactive than I2?
Q.13.Why is helium used in
apparatus?
Q.14.Why does R3P = O exists but R3N = 0 does not?
Q.15.Why nitrogen exists as diatomic molecules and Phosphorus as P4.
Q.16.Why fluronic exhibits only on oxoacid HOF?
Q.17.How are XeO3 and XeOF4 prepared?
Q.18.Why do noble gases have comparatively large atomic size?
Q.19.Draw the structure of xeF, XeOF4 , Xe O3 .
Q.20. Arrange the following in the order of property indicated for each set.
a) F2 , Cl2, Br2, I2 , increasing band dissociation enthalpy
b) HF, HCl, HBr, HI increasing acid strength
c) NH3, PH3, As H3, Sb H3, Bi H3, increasing base strength
d) HOcl, HO cl2, HO cl3, HO cl4 – acid strength
e) H Cl O, H ClO2, H Cl O3, H Cl O4- acid strength
------------------------------------------------------------------------------------------------------------------------------------------------------d and f block elements
Q.1.Scandium ( Z = 21) is a transition element but zinc ( Z = 30) is not.Explain.
Q 2.Though both Cr2+ and Mn3+ have d4 configuration ,yet cr2+ is reducing while M3+ is oxidizing.Explain why?
Q.3.Why do transition elements exhibit higher enthalpies of atomization?
Q.4. What is meant by disproportionation of an oxidation state.Give one example.
Q.5: Why is the highest oxidation state of metal is exhibited in oxides and fluorides only?
Q.6: Calculate the spin only magnetic momentum in case on M2+ ion?( z=27)
Q.7: Actinoid contraction is greater than ;lanthanoid contraction .Why?
Q.8: Explain why Cu2+ ion is not stable in aqueous solution?
Q.9: Define lanthanoid contraction and its consequences ?
Q.10:Draw the structure of Cr2O72-, MnO4-.
Q.11: Explain giving reasons:
a) Transition metals and many of these compound are ferromagnetic.
b) Transition metals generally form colour compound.
c) Transition metals and their many compound act as good catalyst.
d) Oxoanions of metal show higher oxidation oxidation state.
e) Actinoids show large number of oxidation state.
General Principles and process of Isolation of elements
Q.1: Out of C and CO which one is better reducing agent for ZnO.Why?
Q.2: Explain the following
a) Zone refing.
b) Van Arkel.
c) Monds process.
d) Coloumn Chromatography.
Q.3: Write down the reaction taking place in different Zones in the blast furnace during the extraction of iron?
Q.4: Differentiate between roasting and Calcination with example.
Q.5: What is the function of cryolite in the metallurgy of Aluminum/
Q.6: How is Cast iron is different from pig iron?
Q.7: Differentiate between minerals and ores.
BIOMOLECULES
Q.1: Write the reaction to show that all the carbon atoms in glucose are linked in a straight chain.
Q.2: What is meant by in invert sugar?
Q.3: Classify the carbohydrates on the basis molecular Size?
Q.4: Name the hydrolysis product of the following.
a) Lactose b) Sucrose c) Maltose.
Q.5: Sucrose is non-reducing sugar where as lactose is reducing sugar. Explain.
Q.6: Write two functions of carbohydrates in plants.
Q.7: What do you understand by a) glocosidic linkage b) peptide linkage?
Q.8: What is essentially the difference between the α-form of glucose and β-form of glucose? Explain.
Q.9: Enumerate the reaction of D-glucose which cannot be explained by the open chain structure.
Q.10: What happen when D-glucose react with the following reagent?
a) HI
b) Br2
c) HNO3
Q.11: What is glycogen? How it is different from starch?
Q.12: What is basic difference between starch and cellulose?
Q.13: Explain the following terms.
a) Polypeptide
b) Enzymes.
Q.14: Describe what do you understand by primary and secondary structure of proteins?
Q.15: What is meant by denaturation of proteins?
Q.16: What are essential and non-essential amino acids? Give one example of each type.
Q.17:What type of bonding help in stabilizing the α-helix structure of proteins?
Q.18: Differentiate between globular and fibrous proteins.
Q.19:Define thefollowing with example .
a) Zwitter ion.
b) Common type of secondary structure of protein
Q.20: Classify the vitamins on the basis of solubility .
Q.21:Name the vitamin responsible for coagulation of blood.
Q.22: Why vitamin C cannot be stored in our body.
Q.23: Write the structural difference between DNA and RNA .
POLYMER
Q.1:What are natural and synthetic polymers? Give two example of each type.
Q.2: Explain the term co-polymerization and two examples.
Q.3: How does the vulcanization change the character of natural rubber?
Q.4: Differentiate the thermoplastic polymer and thermosetting polymer with example of each.
Q.5: What is biodegradable polymer? Give example of each?
Q.6: What is role of benzoyl peroxide in polymerization of ethene?
Q.7: What are LDP and HDP? How are they prepared?
Q.8: Which factor imparts crystalline nature to a polymer?
Q.9: Write the differences between the following with example
a) Addition and condensation polymer.
b) Chain growth and step growth polymer.
Q.10: Write and draw the structure of monomer of the following.
a) Teflon.
b) PVC
c) Bakelite.
d)PMMA
e) Natural Rubber.
Q.11:How does the double bond in rubber molecules influence their structure and reactivity?
CHEMISTRY IN EVERYDAY LIFE
Q.1: Nme a substance which can be used as an antiseptic as well as disinfectant?
Q.2: What are the main constituent of dettol ?
Q.3: What is tincture of iodine? What is its use?
Q.4: Define the term tranquilizer and give one example
Q.5: Define analgesic, giving one example.
Q.6: Classify the detergent on the basis of ions.
Q.7: What is BHA and BHT?
Q.8: Why aspirin is useful in preventing heart attack?
Q.9: Describe the structure of antibiotic and antiseptic, with example?
Q.10: Define broad spectrum antibiotics .Give one example and state two diseases for which it is prescribed.
Q.11: Describe the following with one example of each.
a) Biodegradable detergent
b) Antifertility drug
c) Preservatives.
d) Antioxidant
e) Artificial sweeteners
Q.12: What is the function of histamine in the body?
Q.13: Account for the following.
a) Diabetic patients are advice to take artificial sweeteners instead of natural one
b) Detergent are non-biodegradable while soaps are degradable.
c) Soap cannot work on hard water.
d) Aspartame can be use only in cold food and drinks.
SURFACE CHEMISTRY
Q.1: Explain the following terms.
a) Absorption and Adsorption.
b) Sorption and desorption.
Q.2: Why adsoroption is always exothermic .
Q,3: How chemisorptions is different from physorption ,explain with example .
Q.4.Explain why finely divided substances is more effective as catalyst .
Q.5: Define adsorption isotherm.Describe Freundilich adsorption isotherm?
Q6: Describe the effect of pressure and temperature on adsorption of gases on solids.Describe the application of
adsorption in controlling of humidity/
Q.7: Whatdo you mean by activity and selectivity of catalyst?
Q.8: Describe the features of shape selective catalyst.
Q.9: What are the factors that influence the adsorption of gas on the solid surface?
Q.10: Write three distinctive features of chemisorptions which are not found in physisorption.
Q.11: Explain how phenomenon of adsorption is applied in the following cases.
a) Production of vacuum.
b) Heterogeneous catalysis.
c) Froath floation process.
Q.12: What are colloids? How are they different from true solution and suspension?
Q.13: Explain the differences among the followings.
a) Multimolecular colloid.
b) Macromolecular colloid.
c) Associated colloid.
Q.14: Explain what is observed.
a) A beam of light is passed through colloidal solution.
b) An electrolyte, NaCl is added to hydrate ferric oxide solution.
c) Electric current is passed through a colloidal solution.
Q.15: Define the following terms.
a) Micelles.
b)Peptisation.
C) Desorption.
Q.16: Define Zeta potential.
Q.17: State Hardy Schulze rule.
Q.18: Explain the following terms.
a) Tyndall effect.
b) Co-agulation.
c) Dialysis
d) Electrophoresis.
SOLID STATE
Q.1: What is semiconductor? Describe the two main type of semiconductor. Explain about their mechanism of
conduction.
Q.2: Explain each of the following with a suitable example.
a) Piezoelectric effect. b) Frenkel defect in crystals. c) Electrical properties of solid.d) paramagnetism.
Q.3: How are the following properties are going to change by Schottky and Frenkel defect?
a) Density
b) Electrical conductivity
Q.4.What is meant by doping in semiconductor?
Q.5: Differentiate between
a) Amorphous and crystalline solid. b) Paramagenetic and diamagnetic substan
c) hcp and bcc.
d) Octahedral and tetrahedral voids. e) metallic and ionic solids. e) conductor,insulator and semiconductor
Q.6: Numerical from the formula of density.Eg Cr crystallizes in bcc structure. It is atomic diameter of 245
pm,Calculate its density.[ At. Mass of Cr = 52 amu and NA= 6 .02 x 10 -23 mol-1]
Q.7: Calculate the density of Cu rystaal that cryatallizes I fcc manner. The radius of Cu atoms is 128 pm.
Q.8:Calculat the value of Avogadro,s no from the following data :density of crystal =2.165 gcm -3 and distance
between Na+ and Cl- 281 pm.
Q.9.: Which point effect doesnot change the density of crystal and why ?
Q.10: How do metallic and ionic substance differ in conducting ?
Q.11: Write three differences in Schottky defect and Frenkel defect ?
Q.12: Acrystalline solid has cubic structure in which W atoms are located at the corner of cube oxygen atoms at the
edge and sodium atoms at the centre . What is the molecular formula of the compound ?
Q.13: Calculate the the following:
i) Number of NaCl units in NaCl units.
II) Number of CsCl unit in CsCl crystal.
Q.14: In a cubic close packed structure of a mixed metal oxide one-eighth of tetrahedral void are occupied by
divalent ions X2+ while one half is occupied by trivalent ions Y3+ .What is te formula of the compound ?
Q.15: Sodium has bcc structure with nearest neighbor distance 365.9 pm . Calculate its density ?
Q.7:Assign reason for the following.
a) Phosphorous doped silicon is a semiconductor.
b) Schottky defect lowers the density of a solid.
c) Impurity doped Silicon is a semiconductor.
d) Frenkel defect are is absent in alkali metal halides.
e) Zink is white but it becomes yellow on heating.
f) Impurity doped Silicon act as semiconductor.
SOLUTION
1:Identify what type of solution, each one of the following is:
a)Copper amalgam
b) A mixture of hydrogen and nitrogen.
c)A carbonated soft drink
d) Moisture in air.
e) Bronze.
2.How will you prepare 0.1 molar and 0.1 molal aqueous solution of a solute whose molar mass is 130gmol-1?
3.Calculate molality of 11.5% of C2H5OH in water?
4. 500cm3 aqueous solution contains 8.0g of dibasic acid whose molar mass is 80gmol-1.The density of the solution is
0.99gmol-1.Calculate the i) molarity. ii) molality iii) mol fraction.
5.Calculate the solubility of CH4 in terms of moles and in 1 kg of benzene at 298 K. The partial pressure of CH4 is 1
bar and KHis 0.5618 kbar.
5. Differentiate between molarity and molality for a solution. How does a change in temperature influence their
values?
6: Define the term osmosis and osmotic pressure. Is the osmotic pressure of a solution a colligative property?
Explain.
7:State the following
a) Henry’s law of partial pressure of gas in a mixture.
b) Raoults law in its general form in reference to solution.
8: Calculate the freezing point of an aqueous solution containing 10.50 g of MgBr2 in 200g of water.( Molar mass of
MgBr2 =184 g, KF for water = 1.86 K kg mol-1.
9: Calculate the boiling point of a solution prepared by adding 15.00g of NaCl to 250.g of water.( K b for water 0.512 K
g mol-1)
10: A solution prepared by dissolving 8.95 mg of gene fragment in 35.0ml of water has an osmotic pressure of 0.335
torr at 250 C.Assuming the gene fragment is a non-electrolyte determine the molar mass.
11. Explain various energy factors associated with dissolution process and how these affect these process.
12: Explain what are isotonic, hypertonic and hypotonic solution
13: What is the value of Vant Hoff factor for 0.2 M solution of acdetic acid which exerts an osmotic pressure of 6 atm
at 250 C.Comment on the molecular state of acetic acid.s
13. Account for the following:
(i) Why the molecular mass becomes abnormal?
(ii) Why water cannot be completely separated from aqueous solution of ethyl alcohol?
(iii) Why the boiling point of solution is higher than pure liquid?
(iv) What role does the molecular interaction play in the solution of alcohol and water?
(v) Why NaCl is used to clean snow from roads?
CHEMICAL KINETICS
Q.1.Distinguish between the rate expression and rate constant of a reaction.
Q.2: Define order of reaction .with example.
Q.3: What do you understand rate law and rate constant of a reaction.s
9(
Ln(R)
Q.4: Define the following terms a) Actvation energy b) threshold energy c) collision frequency of a reaction.
Q.5:Show that for a first order reaction time required for half life is independent of initial concentration.
Q.6: Numerical related to a) t =2.303/tlog[A]0/[A]0 .
b) T1/2 = 0.693/K
7. The rate constant of a reaction is 1.5 x 107 s-1 at 500C and 1000 C 4.5 x 107 s-1.Calculate th e actvation energy?
8. A reaction is 50% complete in 2 hours and 75% complete in 4 hours. What is the order of the reaction?
9. What is meant by elementary steo in a reaction?
10. Write the rate law and order of the following reaction
AB2 + C2→AB2C + C (slow)
AB2 + C → AB2C ( fast )
11. Catalyst have no effect on the equilibrium constant .Why ?
13.
From the given graph concentration Vs time answer the following:
Time (min)
(i)
What is the order of the reaction ?
(ii)
What are the units of rate constant ?
(iii)
If initial concentration of the reactant is half of original concentration , how will t1/2 change ?
(iv)
Draw a plot of log[R]O/[R] Vs time (s) .
14. Answer the following
i) State one condition in which a bimolecular reaction is kinetically of first order?
ii)What is the source of activation energy in a photochemical reaction ?
iii) What is the effect of temperature on rate constant?
iv) Mention the order of following reaction.
a) The thermal decomposition of HI on Gold surface.
b) All natural and artificial radioactive decay.
(v) A first order reaction takes 40 min for 30% decomposition. Calculate t1/2.
(vi) A first order reaction has a rate constant 1.15 x 10-3 sec-1. How long will 5g of this reactant take
to reduce to 3g?
(vii) A first order reaction has half life 1.26x1014 sec. Calculate rate constant.
ELECTROCHEMISTRY
Q.1: Give the mechanism of corrosion.
Q.2: Give the Kohlrausch law.
Q.3: How primary cell is different from secondary cell.
Q.4: Give the cell reaction involved in fuel cell.
5. Calculate the emf of the cell,
Cr(s)/ Cr3+ //Cd2+ / Cd (s) , E0Cr/Cr = -0.70 V ,E0 Cd2+/Cd=-. 40 v
6: Can you store copper sulphate solution in Zinc container?
7. Calculate the emf of the cell in which the reaction
Mg (s) +2 Ag+ (aq) → Mg2+(aq) + 2Ag(s)
When , [Mg]2+ = 1.30 M and [Ag]+ = 1.0 x 10-4 M given , E0Mg2+/Mg =-2.37 V and E0Ag+/Ag =-+0.80 V
8: The resistance of 0.2 M KCl solution in a conductivity cell was found to be 1100 Ω .The conductivity of this cell
was found to be 4.5 x 10-3 S cm-1.Calculate the cell constant.
9: Write the Nerest equation for the following cell.
Mg (s) / Mg2+(aq) // Cu2+(aq) /Cu (s)
10.Determine the equilibrium constant of the following reaction at 298 k :
2Fe3+ + Sn2+ ↔ 2Fe + Sn4+
From the obtained value of equilibrium constant predict whether Sn2+ ions can reduce Fe3+ or not ?
11. The E0 values corresponding to the following two reduction electrode processes are :
(I) Cu+ \ Cu =0.52 v (II) Cu2+ / Cu = 0.16 V Formulate the galvanic cell for combination. Calculate the cell potential
and ∆G0
12. Conductivity of 0.00241 M acetic acid is 7.896 x 10 -5 Scm-1 .Calculate the molar conductivity .If conductivity at
infinite diluation is 390.5 Scm2mol-1.What is the value of dissociation constant /
13. What mass of Zinc can be produced by electrolysis of Zinc Sulphate solution when a current of 0.015 amp is
passed for 15 minutes ?
14. Calculate the potential for half cell containing 0.1 M K2Cr2O7 , 0.20 M Cr3+ and 1.0 x 10-4 M. The half cell reaction
is
Cr2O72- + 14 H+ + 6e →2 Cr3+ + 7 H2O ( E0 = 1.33 V )
15. What is sacrificial protection from rusting ?
16. If a current of 0.5 amp flows through metallic wire for 2 hours, then how many electrons will flow ?
17. HOW potential difference is different from EMF ?
18. How would yoy determine the standard electrode potential of Cu2+ /Cu ?
19. Explain the factors that affect the conductance of ionic conductor ?
20. State two advantages of fuel cell .
TOPIC1.HALOARENES AND HALOALKANES.
2.ALCOHOL,ETHERS AND PENOL
3. ALDEHYDES ,KETONES AND CARBOYLIC ACIDS.
I. How will you obtain the followings :
a) n-propyl iodide from n-propyl bromide.
b) But-2-yne from chloromethane .
c) Bromoethane from ethanol.
d) n-propyl chloride from n-propyl alcohol.
e) Acetic acid from bromemethane.
f) 1-bromopropne to 2-bromopropane.
g)Toluene from chlorobenzene.
h)butan-2-ol to But-2-ene.
i) Isoprpyl alcohol to acetone.
j) 2-Methylpropane-2-ol to 2-methypropene.
k)Acetone to propan-2-ol.
l) propan-2-ol to iodoform.
m)Ethanal to butane-1,3-di-ol.
n)Acetone to propene.
o)Benzaldehyde from Toluene.
p)Bezaldehyde from Benzoic acid.
q)benzaldehyde from benzoyl chloride.
r) But 2 – enal from ethanol
s) Benzoic Acid from ethyl benzene.
t)Ethylamine from propanoic Acid
u) Methyl bromide to acetone.
v) Benzyl chloride to 2-phenyl acetic acid.
II. Assign reason for the followings:
1. Aldehydes and ketones have less boiling points than alcohol.
2. Carbonyl compounds take part in nucleophilic addition not electrophilic addition.
3.Dipole moments of aldehydes asnd ketones are higher than alcohol.
4.It is essential to control PH of the reactions of carbonyl compounds with derivatives of ammonia.
5.Acidicdehydration method is not suitable for convertion od tertiary alcohol to ether.
6.Alcohols are highly soluble in water.
7.Dichloroethanoic acid has lower Pka value than monochloroethanoic acid.
8.esterification is a reversible reaction.
9.electrophilic substitution of benzoic acid takes place at meta position.
10.Carboxilic acid donot exhibit the properties of carbonyl compounds.
III. Give chemical test to distinguish the following:
1.Benzoic acid and phenol.
2.Ehanamide and ethanoic acid.
3.Ethanal. and Propanone.
4.Ehanal and propanal.
5.Acetophenone and Benzophenone.
6.Ethanal and Benzaldehyde.
7.Phenol and Benzyl alcohol.
8.Butan2-ol and 2-methylpropan-2-ol.
IV. Give one example of each of the followings:
1.Fridal Craft Alkylation.
2.Gattermann Reaction.
3.Finkelstein reaction.
4.Fittig reaction.
5.Sandmayer’s reaction.
6.Cross-Aldol condensation.
7.Decarboxylation.
8.H-V-Z reaction.
9.Kolbe’sreaction.
10.Schmidt reaction.
V. Give the IUPAC name of the following:
1.C6H5CH2COOH.
2.CH3CH2CH(CHO) COOH.
3.C6H5CH=CHCOOH.
5. Terephthalic acid.
6.
CH2CHo
7. (CHO)2
8.CH3CH2(CH)CH3CHO
VI.Complete the following reaction.
VII.1.An organic compound A with molecular formula C9H10O forms an orange –red precipitate B 2,4-DPN reagent.
Compound A gives yellow precipitate C on heating with iodine in the presence of NaOH along with colourless
compound D. The compound A does not reduce Tollens’ reagent nor it decolouress bromine water. On drastic
oxidation with Chromic acid , compound A gives a carboxylic acid E with molecular formula C7H6O2.Deduce the
structures of the organic compounds A to E.
2.An unknown aldehyde A on reacting with alkali gives β-hydroxyaldehyde which loses water from an unsaturated
aldehyde but2-enal.Another aldehyde B undergoes disproportionation reaction in presence of Conc. Alkali to form
products C and D .The compound C is an aryl alcohol with formula C7H8O.Identify A TO D .Write all the reactions.
3. An alcohol of unknown structure gave a positive Lucas test in about five minutes.When alcohol was heated with
concentrated H2SO4,an alkene was formed with the formula C4H8. Ozonolysis of this alkene gave a single product
C2H4O.What was the structure of the alcohol.
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