Recently Active Chemistry Questions

The specific rotation of a pure enantiomer is +12 degrees . It is isolated frm a reaction with 20% racemisation and 80%retention . what would be its observed angle of rotation?? plzz tell also how to solve problems like these ...

a sample of C2H2 gas has a pressure of 7.8 kpa. After some time a portion of it reacts to form C6H6 gas . The pressure of mixture of gases is then 3.9 kpa . Assuming constant V and T , find the fraction of C2H2 that has under ...

1) Calculate the molarity and molality of 20% aqueous of ethanol soln by volume (density of the soln=0.960g per cm3) 2) Calculate the volume of 80% H2SO4 (density=1.80g/cc) required to prepare 1L of 20% H2SO4 (density=1.25g/c ...

A glass bulb contains 2.24 L of H2 and 1.12 l of D2 at STP. It is connected to a fully evacuated bulb by a stopcock with a small opening. The stop cock is opend for sometime and then closed. The first bulb now contains .10 g ...

11 moles N2 and 12 moles of H2 mixture reacted in 20 litre vessel at 800K. After equilibrium was reached, 6 moles of H2 was present. 3.58 litre of liquid water is injected in equilibrium mixture and resultant gaseous mixture ...

why ethanoyl chloride and ethanamide do nt show iodoform test? ...

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Say, in phenol, if nitration is carried out, the OH group activates the ring at 3 places. 2 ortho and 1 para. So, why does 47 % ortho nitro phenol form instead of 2/3, ie., 66% ? ...

Q) 2.6g sample of pyrolusite was boiled with 65ml of N oxalic acid and excess of dil. H2SO4. The liquid was then filtered and the residue washed. The filtrate and the washing were mixed and made upto 500ml. 100ml of this soln ...

Van der Waals constants for neon and hydrogen are (a1, b1) and (a2, b2) respectively. The maximum number of moles of Neon which will form a homogeneous mixture with n2 moles of hydrogen at 25°C and constant pressure P is: 1. ...

Q1 what are the reactions involved when phosphoric acid h3po4 is titrated using naoh standard solution? Q2 when h3po4 is titrated using naoh solution, phenopthalien end point and methyl orange end points are observed clearly ...

*Image* please explain the concept clearly Q3.for a reaction ,rate expressions is given as----- RX+OH-=ROH +X- rate=4.7*10-5[RX][OH]+0.24*10-5[RX] wHAT PERCENT OF RX REACT BY SN2 ?WHEN [OH]=0.001M. ...

For the reaction, A⟺B,Kc=([B])/([A]) Kc<1 ⇒([B])/([A])<1⇒[B]<[A].If the concentration of reactants is more then the reaction must proceed in forward direction. But my book is writing that the reverse reaction i ...

1) 4.9g of KClO3, on heating shows a wt loss of 0.384g. What per% of the original KClO3 has decomposed? 2) 1.84g of of a mixture of CaCO3 and MgcO3 was heated to a constant weight. The constant weight of the residue was found ...

1) What is detonating gas? 2)When the mixture of MgCO3 & CaCO3 was heated for a long time, the weight decreased by 50%. Calculate the percentage composition of the mixture. 3)Calculate the weight of V2O5 produced from 2g of V ...

From 200 mg of carbon-dioxide,1021 molecules are removed.The amount of carbon-dioxide left is: a)120 mg b)150 mg c)126.9 mg d)100mg. ...

q.) d activity of a radioactivity isotope falls to 12.5% in 90 days. find decay constant. this ques. is solved in p bahadur.... it has used d eq. - K= 2.303/90 log 100/12.5 but d eq. shud be K= 2.303/90 log 100/87.5 na? since ...

A compound contains 28% N and 72% of a metal by weight.3 atoms of metal combine with 2 atoms of N.Find the atomic weight of metal: a)38 b)30 c)24 d)18 ...

A compound contains atoms of three elements:A, B and C.If the oxidation number of A is +2,B is +5 and C is -2,the possible formula of the compound is: a)A3(BC4)2 b)A3(B4C)2 c)ABC2 d)A2(BC3)2 ...

1) If 5 litres of H2O2 produce 50 lites of O2 at NTP, H2O2 is a)50V b)10V c)5V d)250V I am not able to understand this question. What is it asking? 2)Assuming that petrol is octane & has density 0.8 g/ml, 1.425 litres of petr ...

1.An electrochemical cell is constructed by immersing a piece of copper wire in 50ml of 0.1M CuSO4 soln and " " ' ' zinc wire in " " " ZnSO4 soln. If 50 ml of 1.5 M NH3 is added to CuSO4 soln then Emf of cell is= Ans 0.715V g ...

sorry ...

2.76 gm of silver carbonate on heating strongly gives residue weighing? (Gram atomic mass of silver is 108 gm) ...

15.00 gm of a compound Na2SO4.xH2O contains 2.36*1023 H2O molecules.Find out the value of 'x' ...

*Image* *Image* EDIT:- In Q3 b) part, heat is also there ...

What si the hydrolysiss product ?? *Image* ...

http://targetiit4pcm.lefora.com/2010/06/25/nsec-question-paper-2004-05/ (some errors occurred in copy-pasting from original goiit article) SO pls see link below OR http://www.goiit.com/posts/list/community-shelf-nsec-question ...

1.The hydride which does not react with water a)NH3 b)PH3 c)DIBORANE d)AsH3 2.WHICH ONE IS THE STRONGEST BASE? a)OH- B)HS- c)HSe- d)HTe- 3.GIVE PRODUCT(S). otho-chloro-toluene..REACTS IN PRESENCE OF ..sodamide and liq.ammonia ...

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I'm starting a thread for the resolution of many popular organic doubts which have remained unsolved in this forum. Two of them I managed to solve, for which I provide the links here -: http://targetiit.com/iit-jee-forum/post ...