Transcript
Page 1: COPING WITH CHEMISTRY IS EASY! YOGAnie-images.s3.amazonaws.com/gall_content/2018/11/2018_11$file28_Nov... · etaldehyde and acetone (ii) Phenol and Benzoic acid (iii) Formalde-hyde

Q.1 Write IUPAC name of [Co(CN) H2O(en)2]2+

and

Q.2 What is the effect of pressure on Crystalsolid.

Q.3 Draw the structure of XeO2F2and XeO3

Q.4 What type of isomerism occurs in[CoCl2(en)2]

+

Q.5 What is Henry's Law? Or What is occulu-sion?

Q.6 Why CaCl2 is used to remove snow fromroads in hilly area ?

Q.7 What is meant by hcp and ccp?

Q.8 What is the relation b/w r and R of tetra-hedral and octahedral voids?

Q.9 What is shape selective catalysis. Explainwith ZSM-5

Q.10 (a) What is collision theory frequency?

Q.11 Write short notes : (i) Hardy Schulze Rule(b) Deduce the shape of (HPO3)3 (ii) Peptiza-tion

Q.12 Predict the product of electrolysis ineach of following :(i) An aqueous solution ofCuCl2 withPt electrodes (ii) An aqueous solu-tion of AgNO3 with Ptelectrodes.

Q.13 (a)Determine the Standard Gibbs freeenergy and E0 for the reaction:Zn + Ag2O + H2O------------------>Zn

+++2Ag+2 OH-

Given that E0 Ag+/Ag= 0.34 V, E0 Zn

++/Zn= -0.76

V.(b) Two elements A and B forms compound AB2

and AB4. When dissolved in 20g of Benzene(C6H6), 1g of AB2 lowers the freezing point by2.3K where as 1.0g of AB4 lowers it by 1.3K.

The molar depression constant for benzene

is 5.1Kkg mol-1. Calculate atomic mass of Aand B.

Q.14 Explain (a) why transition metal exhibithighest oxidation state in oxides and fluo-rides. (b) Why La(OH)3 is more basic than Lu(OH)3

Q.15 Differentiate b/w the roasting and calci-nation.

Q.16 (a) What is auto reduction and write thereactions occurring in Bessemer converter

OR(b) Write chemical reactions occurring in theblast furnace and which reaction is endother-mic

Q.17 Arrange the following according to theinstruction: (i) F2, I2, Br2, Cl2 (Increasingorder of bondenthalpy) (ii) H2S, H2O, H2Te,H2Se (Increasing acidic strength)(iii) NH3, PH3, AsH3, BiH3 SbH3 (Increasing or-der of basic character).

Q.18 Write the manufacture of : (i) K2Cr2O7

from chromite ore (ii) KMnO4 by pyrolusiteore

Q.19 (a) Explain Ka2 is much less than Ka1 forH2SO4 (b) Write the mechanism of any two :(i) Dehydration of alcohol into ether (ii) Dehydration of alcohols into ethane (iii) SN2 reaction

Q.20 Explain - (i) FeF6 is outer orbital com-

plex and [Fe (CN)2]-4

is inner orbital complex(ii) [NiCl4]

2-is tetrahedral and Ni (CN)

4--is

square planer. (iii) Ti(H2O)6]3+

is violet incolour

Q.21 Write monomers of : (i) Natural rubber(ii) PHBV (iii) Buna S rubber (SBR)

ORDraw the structure of (i) .D glucose (ii)Amylopectin (iii) Amylose

Q.22 (a) Write short notes on : (i)Cannizaro'sreaction OR Cross Aldol condensation(ii) Carbyl amine reaction OR Clemmensen’sReduction(iii)Hoffamanbromamide degradation reactionOR Gattermann's koch

OR(b) Distinguish b/w following pairs : (i) Ac-etaldehyde and acetone (ii) Phenol and Benzoic acid (iii) Formalde-hyde and Acetaldehyde

Q.23 Alok is 50 years old and has diabetes. Heuses saccharine as sweetening agent in teaand coffee and sugar free in sweets. Gauritoo is diabetic. She controls her sugar level indiet by using less sugar and by exercising. a. Who is able to handle diabetes more effi-ciently and why? b. What value do you derive from this?c. What are the harmful effects of artificialsweeteners.

Q.24 (a) Complete the following chemicalreactions equations:

i) MnO4-aq) + C2O24-(aq)+H

+(aq)

ii) Cr2O72-(aq) + Fe

2+(aq) + H+(aq)

(b) In a pseudo first order hydrolysis of esterin water, the following results were obtained.

i) Calculate the average rate of Rn b/w the timeinterval 30 to 60 second. ii)Calculate the pseudo first order rate con-stant for hydrolysis of ester. /OR(b) For a first order R

n. Show that time required

for 99% completion is twice the time requiredfor completion of 90% of R

n.

Q.25 (a) Silver forms CCP lattice and X- raystudies of its crystals show that the edgelength of unit cell is 408.6 pm. Calculate thedensity of crystal. (b) Why ZnO becomes yel-low on heating?

OR(I) Why do transition metals have higher en-thalpies of atomization?(II) What happens when potassium perman-ganate is heated to 513 K ?(III) Explain giving reason "transition metalsform a large number of complex compounds". (IV) Write two comparisons of variability inoxidation states of transition metals and nontransition elements (p- block elements) ? (V) Write equation for the preparation ofH2SO4.

Q.26 Carry out the following conversions (i) But-1-ene in to But-2-ene (ii) Aniline in toacetanilide (iii)Toluene to Benzoic acid(iv)Methyl Bromide in to 2- Methyl propan-2-ol (v)Formaldehyde into Uropropine.

ORExplain : (i)Aniline can not be prepared byGabriel phalimide Synthesis(ii)Carboxylic acids are more acidic than phe-nols(iii) Tert alkyl halide can not be used inWilliamson's synthesis to prepare tert alkylether(iv) Chloroform if kept in air tight darkcoloured bottles and ethanol in added.(v) Alkyl halides on reaction with K.C.N to givecyanide while on reaction with AgCN to giveIs cyanide.

06 “Believe in yourself! Have faith in your abilities! Without ahumble but reasonable confidence in your own powers you

cannot be successful or happy.” —Norman Vincent Peale MOCK PAPERS

M O C K P A P E RCHEMISTRY

CLASS XII, CBSE

GENERAL INSTRUCTIONS1. All questions are compulsory.

2. Question Nos. 1 to 5are very short answer ques-tions and carry 1 mark each.

3. Question Nos. 6 to 10 are short answer ques-tions and carry 2 mark each.

4. Question Nos. 11 to 22 are short answer ques-tions and carry 3 mark each.

5. Question Nos. 23 carry 4 mark each.QuestionNos. 24 to 26 carry 5 mark each.

6. Use log tables if necessary, use of calculatorsis not allowed.

These questions and the marks along-side are meant for practice purpose

only. Students are advised to check for-mat, syllabus and marks for Board testpapers with their teachers. Questions

have been given by teachers and NIE isnot responsible for them.

YOGADURING EXAMS COPING WITH CHEMISTRY IS EASY!

Exam cell, St. Kabir High School, Ahmedabad, presents Chemistry paper for you to practice ...

HOW TO:

STAGE 1: Sit in a cross-legged pose withhands resting on the knees. Close your eyes.Slowly move the head forward and try totouch the chest with the chin. Move the headas far back as comfortable. Feel the stretch ofthe muscles in the front and back of the neck.Practise 10 times.

STAGE 2: Relax the shoulders, slowly movethe head to the right, bringing the right earclose to the right shoulder without raising theshoulders and vice-versa. Do not strain,touching the shoulder is not necessary.Practise 10 rounds.

STAGE 3: Keep the head upright and the eyesclosed. Gently turn the head to the right sothat the chin is in line with the right shoulder.Feel the release of tension in the neck mus-cles and the loosening of the neck joints.Slowly turn the head to the left as far as com-fortable. Practise 10 times on each side.

STAGE 4: Slowly rotate the head downwards,to the right, backwards and then to the left ina relaxed, smooth, rhythmic, circular move-ment. Feel the shifting stretch around theneck and the loosening up of joints and mus-cles of the neck. Practise 10 times clockwiseand then 10 times anti-clockwise.

BENEFITS: All the nerves connecting differ-ent organs and limbs of the body passthrough the neck. This means that the mus-cles of the neck and shoulders, accumulatetension, especially after prolonged work atthe desk. This asana releases tension, heavi-ness and stiffness in the head, neck andshoulder region.

Everyone has their ownidea about the best placeand time to study.

Whether it's your bedroom atnight or the library afterschool, find a study space anda regular study time that worksfor you and stick with it.

IDEAL STUDY SPACE: It shouldbe quiet, comfortable and dis-traction-free. It should make youfeel happy and inspired. Deco-rate it with your favourite pic-tures or objects. If you want tolisten to music or burn incense,pick a space that lets you do that.

OBSERVE YOUR BEST TIME : Somepeople are early risers, whileothers study better at night, soselect a time that suits you andmake optimum utilisation of it.Don't study much beyond yourusual bedtime – pushing your-self late at night can make youtoo tired to study properly.

Choose yourspace and

time

Yes, approx. 10% ofyour marks dependson this night, make

a great use of this night,not in the study but intaking rest, making yourmind feel relaxed.

This is exactly whatyou need to do.

1Make yourself forgetthat tomorrow is your

exam, feel free like abird.

2Do not ever try to re-vise your study stuff,

as this is not one nightfight.

3Sleep earlier as muchas possible, and take a

long sleep. This will helpyou to reset your brainand remember the thingsmore accurately at thetime of the exam.

The Nightjust beforethe examThis is a good snack to

have, as it providesinstant energy and

perks you up. It is easy tomake and not messy to eat.

INGREDIENTS Chopped peanuts Sugar ButterMETHOD Roast peanuts and take offthe skin. Coarsely chop them or

coarse grind them. In a pan, melt some butterand add sugar. When the sugar turns lightbrown add the peanuts. Stir it gently, so that themixture does not burn. Take it off the flame after5 minutes and allow it to cool.Your peanuts are ready!K SRI SANJANA, class VII,

Whitefield Global School,

Bengaluru

CARAMELISED PEANUTS

QD e s c r i b ebriefly the

study plan youfollowed whilepreparing for theboards?

I made a timetable for each dayand subject and followed it strict-ly, besides revising all my workon the day it was taught – so itbecame easy for me to revise dur-ing boards. I tried to recall everychapter whenever I had time.Solving sample papers gave meextra practice.

QWhat were your key chal-lenges and how did you

tackle them?

The challenge that every childfaces is how to manage time. I

initially faced this challenge butwith regular learning, revisionand adherence to a timetable, Iwas able to overcome it.

QHow did you deal withpressure to perform?

I made myself believe that Icould do well and nothingis difficult if youhave the passionto achieve it. Mystrong deter-mination andthe encour-aging wordsof my par-ents andt e a c h e r shelped me dealwith pres-sure. Also,

my parents never pressured meto score good grades, they justtold me to give my 100% in theexams...

QHow did you motivateyourself?

I never considered my marks tobe the best. I always told myselfthat I have a long way to go. This

is just the beginning. I con-stantly encouraged

myself to beat myown scores in

every exam...

QHowd i d

you bal-ance ac-

ademics with other activities?

I set aside time from my stud-ies for physical exercise as ahealthy body creates a healthymind. Physical fitness and men-tal fitness are interlinked and Inever compromised with myphysical fitness. In fact, I playedoutdoor games like badmintonfor an hour every day.

QWhat would you like totell future aspirants?

Just believe in yourself andkeep working hard throughoutthe year and you will achievethe desired results! Don't leaveany topic unread; always re-member even the smallest linein your NCERT textbook is veryimportant.

“NCERT TEXTBOOK IS IMPORTANT”Aayushi Muley, a class x student from Delhi Public School, Ahmedabad, scored 97.2% inher board exams. She shares her success mantra with NIE…

Sunaina Rekhi comes up withquick yoga asanas that helpyou to relax while studying

t/s 0 30 60 90

[Ester]/mol L-1

0.55 0.31 0.71 0.085

Greeva Sanchalana (neck movements)

OC2H5NO2

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