Chemistry Question Bank

A hydrocarbon contains 80% carbon. What is the empirical formula of the compound? (KCET 2009 )

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…

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

Which of the following will not give test for ‘N’ in sodium extract?

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

Sulphur is estimated by Carius method in the form of

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

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

When 0.32g of a compound is heated with conc. HNO₃ and BaCl₂, 0.932g BaSO₄ is obtained. The percentage of sulphur in the compound is

Phenols contains acidic H it reacts with KOH.

Which of the following observations is correct and is used in the identification of carboxylic acids?

Violet coloured complex obtained in the detection of sulphur is (AFMC 2010) (a) Na Fe(NO)(CN) (b) Na Fe(ONS)(CN) (c) Na Fe(CN) NOS

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.

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

Which of the following statements is wrong?

0.395 g of an organic compound by Carius method for the estimiation of sulphur gave 0.582 g of BaSO₄. The percentage of sulphur in the compound is–

How will you separate iodine from sodium chloride?

A mixture of acetone and CCl₄ can be separated by

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…

Chemical formula of Prussian blue is (AFMC 2010) (a) Na Fe(CN) (b) K Fe(CN) (c) 6 3 Fe Fe(CN)

In an organic compound, phosphorus is estimated as (AFMC 2010) (a) Mg P O (b) Mg PO (c) H PO (d) P O Ans. (a) Sol. In Carius method, the weighed organic compound (containing phosphorus) is heated with conc. HNO follow…

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)

Paper chromatography is an example of : (NEET 2020)

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

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)