19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
In Duma's method of estimation of nitrogen 0.35 g of an organic compound gave 55 mL of nitrogen collected at 300 K temperature and 715 mm pressure. The percentage composition of nitrogen in the compound would be (Aque…
The Lassaigne's extract is boiled with conc. HNO3 while testing for halogens. By doing so it (CBSE AIPMT 2011)
1.2g of organic compound on Kjeldahlisation liberates ammonia which consumes 30 cm3 of 1N HCl. The percentage of nitrogen in the organic compound is (KCET 2011)
In Duma's method of estimation of nitrogen 0.35 g of an organic compound gave 55 mL of nitrogen collected at 300K temperature and 715 mm pressure. The percentage composition of nitrogen in the compound would be (Aqueo…
The Lassaigne's extract is boiled with conc. HNO3 while testing for halogens. By doing so it (CBSE AIPMT 2011)
Which of the following compounds will not give answer Lassaigne’s test for nitrogen (DPMT 2010)
In Carius method of estimation of halogens, 0.099 g organic compound gave 0.287. The percentage of chlorine in the compound will be (Haryana PMT 2010)
0.765 g of an acid gives 0.535 g of CO2 and 0.138 g of H2O. Then, the ratio of the percentage of carbon and hydrogen is (JCECE 2010)
In Kjeldahl's method, ammonia from 5g of food neutralizes 30 cm of 0.1 N acid. The percentage of nitrogen in the food is (KCET 2010)
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 foll…
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…
Chemical formula of Prussian blue is (AFMC 2010) (a) Na Fe(CN) (b) K Fe(CN) (c) 6 3 Fe Fe(CN)
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
Sublimation is a process in which a solid (KCET 2010)
Which of the following compounds gives blood red coloration when it Lassaigne’s extract is treated with alkali and ferric chloride? (DPMT 2009)
A hydrocarbon contains 80% carbon. What is the empirical formula of the compound? (KCET 2009 )
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 2…
The masses of carbon, hydrogen and oxygen in an organic compound are in the ratio 6: 1: 8 respectively. Which of the following pairs of formulae correspond to the above information? (Kerala CEE 2009) (a) CH O and CH …
In the Duma's method of estimation of nitrogen, the nitrogen in the organic compound is finally converted into (Kerala CEE 2009)
In an organic compound, C 68.5% and H 4.91% . Which empirical formula is correct for it? (CPMT 2009) (a) C H (b) C H O (c) C H O (d) C H O Ans. (b) Sol. Element At. Percent No. of Simple molar wt. composition moles …
A hydrocarbon has carbon and hydrogen. Its molecular weight is 28. Its possible formula would be (AFMC 2009) (a) C H (b) C H (c) CH (d) C H Ans. (b) Sol. Compound Molecular weight C H 12 3 x C H x CH C H x Henc…
Assertion (A): S || NH – C– NH gives red color in Lassaigne’s test Reason (R): Compounds having N along with C give red colour in Lassaigne’s test. (AIIMS2009)
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)
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)
Anthracene can be purified by