19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Hydrogen can be prepared by the action of dil. H₂SO₄ on
Blackened oil painting can be restored into original form by the action of
Which of the following reactions is not used in preparation or deuterium compounds using heavy water?
When zeolite (hydrated sodium aluminium silicate) is treated with hard water the sodium ions are exchanged with
Which of the following is not correct regarding the electrolytic preparation of H₂O₂?
Assertion: In alkaline medium, H₂O₂ reacts with potassium ferricyanide. Reason : H₂O₂ is a strong reducing agent.
Assertion: Anhydrous BaO₂ (barium peroxide) is used for preparing H₂O₂. Reason: Hydrated BaO₂ is not available.
Assertion: Permanent hardness of water can be removed by using washing soda. Reason: Washing soda reacts with soluble calcium and magnesium chlorides and sulphates in hard water to form insoluble carbonates.
Assertion: Among the two OH bonds in H₂O molecule, the energy required to break the first OH bond and the other OH bond is same. Reason: This is because the electronic environment around oxygen is the same even after …
Assertion: Increasing pressure on pure water decreases its freezing point. Reason: Density of water is maximum at 4° C.
A commercial sample of hydrogen peroxide is labelled as 10 volume. Its percentage strength is nearly
The volume of oxygen liberated from 15 mL of 20 volume H₂O₂ is
What is the volume of “20 volume H₂O₂” required to get 5000 cm3 of oxygen at STP ?
Which of the following equation depicts reducing nature of H₂O₂?
Which of the following cannot be used as a test for H₂O₂ ?
H₂O₂ is obtained by which of the following?
The molecular formula of a commercial resin used for exchanging ions in water softening is C₈H₇SO₃Na (Mol. wt. 206). What would be the maximum uptake of Ca²⁺ ions by the resin when expressed in mole per gram resin?
Match the column I with column II and mark the appropriate choice. Column I Column II (A) Clark’s method (i) Na₆P₆O₁₈ (B) Calgon’s method (ii) NaAlSiO₄ (C) Ion-exchange method (iii) RSO₃H (D) Synthetic resins method (…
Match the column I with column II and mark the appropriate choice. Column I Column II (A) Syngas (i) Na₆P₆O₁₈ (B) Calgon (ii) NaAlSiO₄ (C) Permutit (iii) CO + H₂ (D) Producer gas (iv) CO + N₂
During hydrate formation from aqueous solution, water can be associated in different forms. Indicate the wrong combination. (i) Coordinated water – [Cr(H₂O)₆]3+ 3Cl– (ii) Interstitial water – BaCl₂.2H₂O (iii) Hydrogen…
Study the following reactions and mark the correct properties shown by water. (i) SO₃ + H₂O → H₂SO₄ (ii) Cl₂O₇ + H₂O →2HClO₄ (iii) CaO + H₂O →Ca(OH)₂ (iv) Na₂O + H₂O →2NaOH
Match the reaction of column I with their types given in column II and mark the appropriate choice. Column I Column II (A) H O NH NH OH (i) Self ionisation of H₂O (B) FeCl 3H O → Fe(OH) 3HCl (ii) Decomposition (C) H O…
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°. (iii…
Phosphorus cannot form PH₅ with its outer electronic configuration as 3s2, 3p3 because
Match the column I with column II and mark the appropriate choice. Column I Column II (A) NaH (i) Interstitial hydride (B) CH₄ (ii) Molecular hydride (C) VH₀.56 (iii) Ionic hydride (D) B₂H₆ (iv) Electron-deficient hyd…