✓✗In Lassaigne’s test for sulphur, the extract acidified with acetic acid gives a black precipitate with

✓✗In Dumas’ method of estimation of nitrogen, 0.35 g of an organic compound gave 55 mL of nitrogen collected at 300 K and 715 mm pressure. The percentage of nitrogen in the compound would be (aqueous tension at 300 K = 15 mm)

✓✗Which of the following neutral molecules acts as a nucleophile?

✓✗Which statement is correct about the resonance hybrid of the nitromethane molecule, CH₃NO₂?

✓✗The IUPAC name of the compound CH≡C−CH=CH₂ is

✓✗Which of the following acids is the weakest?

✓✗Which of the given compounds can exhibit tautomerism?

✓✗Which one of the following orders is correct regarding the −I effect of the substituents?

✓✗The IUPAC name of CH₃CH₂Cl is

✓✗Which of the following statements are correct?
A. Kjeldahl’s method is not applicable to compounds containing nitrogen in a ring.
B. In Dumas’ method, nitrogen is estimated as N₂ gas.
C. In the Carius method, halogens are estimated as silver halides.
D. Oxygen is estimated directly by heating with CuO.
Choose the correct answer from the options given below.

✓✗Which of the following groups shows +I effect?

✓✗The enolic form of ethyl acetoacetate, CH₃−C(OH)=CH−COOC₂H₅ (in equilibrium with CH₃COCH₂COOC₂H₅), has

✓✗The C−C bond lengths in ethane, ethene, benzene and ethyne follow the order

✓✗The resonance energy of a molecule is the difference in energy between

✓✗Phosphorus in an organic compound is estimated as