19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Which of the following statement regarding protium, deuterium and tritium is not correct?
Hydrogen resembles halogens in many respects for which several factors are responsible. Of the following factors, which one is the most important in this respect?
Like alkali metals, hydrogen forms I. Oxides and oxyacids. II. Halides and interhalides. III. Oxides, halides and sulphide.
Hydrogen has resemblance to alkali metals as well as with halogens. The reason is that
In elemental form, hydrogen exists as
Point out the element which has simplest atomic structure among all the elements around us in nature.
The density of water is less in its solid state because
Liquid water is denser than ice due to
Which gas is produced when calcium nitride (Ca3N2) is hydrolysed by water?
Given below are two reactions of water with sodium and carbon dioxide. What is the nature of water in these reactions? (i) 2Na + 2H2O -> 2NaOH + H2 (ii) 6CO2 + 12H2O -> C6H12O6 + 6H2O + 6O2
Presence of water can be detected by
Which of the following reactions shows reduction of water ?
Temporary hardness of water is due to the presence of
The exhausted cation and anion exchange resin beds are regenerated by treatment with
Which of the following compounds is used for water softening? (a) Ca PO (b) Na PO (c) Na P O (d) Na HPO
Number of parts by weight of calcium carbonate present in …….defined as the degree of hardness of water. Fill the blank with an appropriate statement.
The hardness of water is estimated by
A water sample is said to contain permanent hardness if water contains
Which of the following is not a disadvantage of using hard water?
The temporary hardness of water due to calcium bicarbonate can be removed by adding
The formula for permutit or zeolite which is used as softener in ion-exchange method is
The formula of exhausted permutit is
Which of the following is a true structure of H2O2 in solid phase ? (a) (b) (c) (d)
When CO2 is bubbled through a solution of barium peroxide in water
Which of the following metals evolves hydrogen on reacting with cold dilute HNO3? (AIPMT 1989)