19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Which of the following will not give test for ‘N’ in sodium extract?
Azeotropic distillation is used only to seperate azeotropes ie. constant boiling mixture. Here acetone & CCl₄ are not azeotropic mixture. Hence (a) is not correct.
Compounds which do not contain halogen but give positive Beilstein test?
1 percent composition of an organic compound A is carbon: 85.71% and hydrogen 14.20% . Its vapour density is 14. Consider the following reaction sequence Cl /H O (i) KCN/EtOH (ii) H O A B C → → Identify C (EAMCET 2009…
Sulphur is estimated by Carius method in the form of
Lassaigne’s test is not shown by diazonium salts. Why?
Which of the following statements is wrong?
The compound formed in the positive test for nitrogen with the Lassaigne solution of an organic compound is (RPMT 2010) (a) 6 3 Fe Fe(CN) (b) Na Fe(CN) (c) Fe(CN) (d) Na Fe(CN) COS Ans. (a) Sol. 3Na Fe(CN) 4Fe → 6 3 P…
Sodium nitrorusside Na₂[Fe(CN)₅NO] is used as reagent for detection of ______ and the compound formed is ____.
The prussian blue colouration obtained in the test for nitrogen in the organic compound is
CCl₄ & acetone differ in their boiling Point. So it can be seperated through fractional distillation. Hence (b) is correct.
The Lassaigne's extract is boiled with conc. HNO₃ while testing for halogens. By doing so it (CBSE AIPMT 2011)
Phenols contains acidic H it reacts with KOH.
Which of the following observations is correct and is used in the identification of carboxylic acids?
The Lassiaigne’s extract is boiled with conc. HNO₃ while testing for halogens. By doing so it (AIPMT Prelim 2011)
In the estimation of sulphur by Carius method 0.480 g of an organic compound given 0.699g of barium sulphide. The percentage of sulphur in this compound is (atomic masses : Ba = 137.5 = 32 and O = 16) (Kerala PET 2012)
An organic compound is heated with HNO₂ at 0 °C and then the resulting solution is added to a solution -napthol whereby a brilliant red dye is produced. The observations indicate that the compound possesses.
The Lassaigne's extract is boiled with conc. HNO₃ while testing for halogens. By doing so it (CBSE AIPMT 2011)
Acetic acid and CH₃COCl can be distinguished by
0.30 g of an organic compound containing C, H and O on combustion yields 0.44 g CO₂ and 0.18 g H₂O. If one mole of compound weighs 60, then molecular formula of the compound is (Karnataka CET 2015)
In the Lassaigne’s test for the detection of nitrogen in the organic compound, the appearance of blue coloured compound is (West Bengal PMT 2015)
Paper chromatography has following mobile and stationary phases respectively (Bihar CECE 2015)
The most suitable method of separation of 1: 1 mixture of ortho and para-nitrophenols is (NEET 2017)
Phenol can be distinguished from ethanol by
Paper chromatography is an example of : (NEET 2020)