19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Liquid N₂O₄ self-ionizes as
Which of the following reactions gives reasonably pure NO?
At present, HNO₃ is industrially prepared by the
Phosphorus reacts with concentrated HNO₃ to produce
Iodine reacts with concentrated HNO₃ to produce
Gold reacts with aqua regia forming
Platinum reacts with aqua regia to produce chloroplatinic acid represented by the formula
Which one of the following is not an ore of phosphorus?
Which of the following structures represents hypophosphoric acid? (a) (b) (c) (d)
The most stable oxidation states of nitrogen are
The element which forms oxides in all oxidation states +I to + V is :
Which of the following fertilizers on repeated application would increase the acidity of the soil?
The bond order in the NO molecule is
Which of the following statements is correct?
The most stable allotropic form of phosphorus is
Red phosphorus is less reactive than white phosphorus because (a)the P—P bond length is greater in red phosphorus
Group 16 elements (except polonium) are called chalcogens because
Which of the following statements is correct for sulphur?
All the halogens are coloured. The colours arise due to
In pyrophosphoric acid the number of hydroxyl groups are (UP CMT 2013)
The increases order of reducing power of halogen acid is (Manipal 2013)
The correct arrangement of following acids of phosphorus in the increasing order of oxidation state of phosphorus is (Guj CET 2014)
A gas ‘X’ is used in filling balloons for meteorological observations. It is also used in gas-cooled nuclear reactors. Here, the gas X is (AIIMS 2018)
Affinity for hydrogen decreases in the group from fluorine to iodine. Which of the halogen acids should have highest bond dissociation enthalpy? (AIIMS 2019)
Which of the following statements is not true for halogens? (NEET 2019)