Chemistry Question Bank

Assertion (A): During test for nitrogen with Lassaigne’s extract on adding FeCl₃ solution sometimes a red precipitate is obtained. Reason (R): Sulphur is also present (AIIMS₂₀₀₇)

Which of the following is the test of alcohol?

Sodium nitrorusside Na₂[Fe(CN)₅NO] is used as reagent for detection of ______ and the compound formed is ____.

Lassaigne’s test is not shown by diazonium salts. Why?

The prussian blue colouration obtained in the test for nitrogen in the organic compound is

Acids reacts with KOH to form salt.

Compounds which do not contain halogen but give positive Beilstein test?

If N and S both are present in an organic compound during Lassaigne’s test, both will change into

An organic compound contains C, H, N, S and Cl. For the detection of chlorine, the sodium extract of the compound is first heated with a few drops of concentrated HNO₃ and then AgNO₃ is added to get a white ppt. of Ag…

Assertion (A): Oils are purified by steam distillation. Reason (R): The compounds which decompose at their boiling points can be purified by steam distillation. (AIIMS₂₀₀₈)

The Lassiaigne’s extract is boiled with conc. HNO₃ while testing for halogens. By doing so it (AIPMT Prelim 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?

0.2475g of an organic compound gave on combustion 0.4950g of carbon dioxide and 0.2025g of water. The percentage of carbon and hydrogen are:

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.

Which of the following statements is wrong?

Sulphur is estimated by Carius method in the form of

An organic compound having carbon, hydrogen and sulphur contains 4% of sulphur. The minimum molecular weight of the compound is

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)

Which of the following compounds gives blood red coloration when it Lassaigne’s extract is treated with alkali and ferric chloride? (DPMT 2009)

Sublimation is a process in which a solid (KCET 2010)

Which of the following compound is/are purified by sublimation?

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)

The most suitable method of separation of 1: 1 mixture of ortho and para-nitrophenols is (NEET 2017)

Paper chromatography has following mobile and stationary phases respectively (Bihar CECE 2015)