19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
At its melting point, ice is lighter than water because (AIPMT 1992)
Water gas is produced by (AIPMT 1992)
Which of the statements given below are true for the water molecule structure? (i) Oxygen undergoes sp3hybridisation. (ii) Due to presence of two lone pairs of electrons on oxygen the H–O–H bonds angle is 118.4°. (ii…
Choose the correct statement about the given figures.
Phosphorus cannot form PH5 with its outer electronic configuration as 3s2, 3p3 because
One would expect proton to have very large (AIPMT 1993)
Hardness of water is due to the presence of salts of (AMU 2007)
Which of the following is responsible for the permanent hardness of water? (CPMT 2010)
The formula for permutit or zeolite which is used as softener in ion-exchange method is
Which of the following is not a disadvantage of using hard water?
The formula of exhausted permutit is
The temporary hardness of water due to calcium bicarbonate can be removed by adding
Which of the following is a true structure of H2O2 in solid phase ? (a) (b) (c) (d)
A water sample is said to contain permanent hardness if water contains
When CO2 is bubbled through a solution of barium peroxide in water
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
Which of the following metals evolves hydrogen on reacting with cold dilute HNO3? (AIPMT 1989)
Presence of water can be detected by
Which of the following reactions shows reduction of 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
Temporary hardness of water is due to the presence of
Liquid water is denser than ice due to
The exhausted cation and anion exchange resin beds are regenerated by treatment with