Sunday, November 29, 2015

Chemistry guides for +2 students

Ans:   (look at the post that i posted before)























Chemistry guides for +2 students

Aja ko topics chai  Haloalkane;


 important questions from this topics are---

Very short ques....-- 

1-a haloalkane @ reacts with aq.Naoh to give isopropyl alcohol.what major product would you get when @ is heated with Na in presense of dry ether?

2-give the major products in the following questions:
  i=      Br
          |      Na/ether
      CH3-CH-CH3---------->

  ii=            LiAlH4
      CH3-CH3-Br---------->

3-Give the IUPAC name of X and Y in the following reactions.
                 AgCN       LiALH4
    CH3-CH2-Br----------->X------------>Y

4-Starting from idomethane,how would you prepare:
  i)ethane  ii)ethene

5-write down the structure of secondary haloalkane of c3H7X.
  What happens when the secondary haloalkane is heated with Na in presense of dry ether ?

6-Give the IUPAC name of X and Y in the following reactions.
                 AgCN       LiALH4
    CH3-CH2-I----------->X------------>Y

7-Convert 1-bromopropane to 2- bromopropane.

8-convert 1-chloropropane to 2- chloropropane

9-Identify the major product A and B in the following reations:
          Mg           H20  
  C2H5Br----------->A----------->B

10- Identify the major product A and B in the following reations:
            alc.KOH      i) O3  ii)(Zn/H20)
 CH3-CH2-Br---------->A----------------------->B

11-What happens when chlorofom is heated with silver powder?

12-Write the avction of monohydroxy benzene with chloroform in presense of alc.NaOH.

13-A primary haloalkane(X),if allowed to reacts with KCN yields a compounds (Y),which on hydrolysis give propanoic acids.
   Identify X and Y.
14-Convert bromoethane into ethyne.

15-Why does chloroform not give white precipitate with silver nitrate?

16-Give uses of chloroform.
17- why is chloroform stored in a dark brown bottle?


SHORT QUESTION;
1-Describe laboratory method of preperation of chloroform.How does chloroform reacts with acetone?

2- Give the chemical reactions for the preparation of chloroform from ethanal.what happens when it is heated with silver powder?
  
3-How would you obtain:
  a)ethane from bromoethane
  b)ethyne from chloroform
4-Give reation to convert A into ethanoic acid.

5- write ANY three methods of preparations of Iodoethane.What happens when Idoethane is heated with
  i)Sodium in present of dry ether
  ii)alc.NaOH
6-Starting from chloroform,how would you prepare:
 i)ethyne   ii)methane  iii)chlopropicrin  iv)carbonyl chloride  v)chloretone

7-Describe the lab preparation of ethyl iodide from ethyl alcohol and PI3 or red phosphorous and iodine.

8-what happens when chloroform is allowed to react with NaOH solution?


LONG QUESTIONS:
Important questions are;;;
a)lab p[reparation of chloroform
b)Inductive effects
c)wurtz reactions
d)markkovnikoffs rule

ans will be in next post

Saturday, November 28, 2015

Chemistry guides for +2 students

Ans : (look at the post that i posted before)










Chemistry guides for +2 students

(for 12th grade)
HI +2 appearing students this blog will help you for your good grades in exam for those who are appearing  this years.
Our chem is divided into three groups;
1-physical chemistry-
2-Organic chemistry-
3-inorganic chemistry-

Aja hami organic ko chapter tarfa janxau kinaki yo lastai jhyau raw garo xa ;
At first yesko imp topic haru
1-Aromatic Hydrocarbons
2-Haloalkanes and Haloarenes
3-Alcohols and Phenols
4-Ethers
  -Aliphatic ethers
  -Aromatic ethers 
5-Aldehydes and Ketones
6-Carboxylic acid
7-Nitro compounds
8-Amino compounds
9-Molecules of life
10-Chemistry in service to mankind

Aja ko topics chai  Aromatic Hydrocarbons;


 important questions from this topics are---
1- How would you prepare benzene from..
    i=ethyne
    ii=sodium benzoate
2- state huckles rule for aromaticity.
3-write resonance hybrid structure of arene containing meta director and ortho director saubstituents    of each.
4- why is benzene called aromatic compound according to huckles rule?
5-what happens when:
    -sodium benzoate is heated with soda lime
    -phenol is heated with zinc dust
6-How would you obtain benzene from
   -sodium benzoate
   -toulene
7-write notes on -
   -fridel crafts alkylation
   -fridel crafts acylation

Answer will be in next post
stick around :D








Dal Bhat and Tarkari

(in nepali)
.
Yedi tapai nepali ho bhaney yaha hajir hunu hos ani padhnuhos

dal bhat raw tarkari kasari banauney taw????
At first for bhat yesko recipes haru
1-pani(water)
2-rice cooker or pressure cooker
3-rice grains(chamal)
4-ghee(ghew)

process-
 Suruma pani halnus about 150ml for 100gm of rice in a vessel for about 1hr mitho swad ko lagi
ani 1hr paxi teslai rice cooker athawa pressure cooker ma halnuhosh and ghee halna chai nabirshinu.
    Ani tyo bhado lai chop dinush ani heat gardinush.after about 30 min or later tapai ko bhat tayar huney xa ani thal ma paskinuhosh ani guam guam khanu hosh .:D

For Dal yesko recipe haru
1-pani(water)
2-rice cooker or pressure cooker
3-(lentil) wa kalo dal,mushuro ko dal,chana ko dal...etc
4-ghee(ghew)

process-
Abo dal pakaum hai taw.Tesko lagi suruma dal lai pani ma 2hr ko lagi bhijaunu hosh.Tespaxi tyo bhijako dal lai guwammai pressure cooker ma halnuhosh and pani halnuhosh afai adkalnu hola tespaxi
ghew halera pakaidinush birko ley chopnu hosh and wait it for about 30 -45 min raw 3 choti sisti lagey paxi gwam gwam bhat ma halera khanu hosh.

For tarkari yesko recipe haru thupro xan
tara aja ma tailai sagg banauna sikauxu
1-sagg(leaves of mustard or leaves of raddish)
2-mustard oil
3-frying pan

process-
Sagg pahila kelaunu hosh .Tespaxi majhaley pakhalera tato tel(hot oil)ma chopera frying pan ma bhutnu hosh (fry it) after some time teslai chalaunu hosh ani chopnu hosh (lid it) after 3 min teslai jhiknu hosh raw plate ma hali bhat raw dal sita khanu hosh.

jai nepal