17 questions from 2021
The set in which compounds have different nature is:
Which one of the following correctly represents the order of stability of oxides, \( X_2O \). (\( X \) = halogen)?
The oxide without nitrogen-nitrogen bond is:
Given below are the statements about diborane.\( (a) \) Diborane is prepared by the oxidation of \( \mathrm{NaBH_4} \) with \( \mathrm{I_2} \)\( (b) \) Each boron atom is in \( sp^{2} \) hybridized state\( (c) \) Diborane has one bridged \( 3 \) centre-\( 2 \)-electron bond\( (d) \) Diborane is a planar moleculeThe option with correct statement(s) is:
Chemical nature of the nitrogen oxide compound obtained from a reaction of concentrated nitric acid and \( \mathrm{P_4O_{10}} \) (in \( 4:1 \) ratio) is:
The reaction of white phosphorus on boiling with alkali in inert atmosphere resulted in the formation of product ‘A’. The reaction of \( 1 \) mol of ‘A’ with excess of \( \mathrm{AgNO_3} \) in aqueous medium gives __________ mol(s) of \( \mathrm{Ag} \). (Round off to the Nearest Integer).
Which one of the following is formed (mainly) when red phosphorus is heated in a sealed tube at \( 803 \, \text{K} \)?
The major component/ingredient of Portland Cement is:
The ratio of number of water molecules in Mohr's salt and potash alum is ______ \( \times 10^{-1} \). (Integer answer)
The number of non-ionisable hydrogen atoms present in the final product obtained from the hydrolysis of \( \mathrm{PCl}_{5} \) is:
Among the following allotropic forms of sulphur, the number of allotropic forms, which will show paramagnetism is ________.\\( (A) \\ \alpha\text{-sulphur} \\\qquad (B) \\ \beta\text{-sulphur} \\\qquad (C) \\ \mathrm{S_2}\text{-form} \\)
In polythionic acid, \({H_2S_xO_6} \) (\( x = 3 \) to \( 5 \)) the oxidation state(s) of sulphur is/are:
Which one of the following compounds of Group-\( 14 \) elements is not known?
In which one of the following molecules strongest back donation of an electron pair from halide to boron is expected?
The species given below that does NOT show disproportionation reaction is:
The set that represents the pair of neutral oxides of nitrogen is :
The number of \( \mathrm{S{=}O} \) bonds present in sulphurous acid, peroxodisulphuric acid and pyrosulphuric acid, respectively are:
