19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Assertion (A): H₂SO₄ acts as a base in the presence of HClO₄. Reason (R): Perchloric acid is stronger acid than H₂SO₄.
The solubility products of MA, MB, MC and MD are 1.8 × 10–10, 4 × 10–3, 4 × 10–8 and 6 × 10–5 respectively. If a 0.01 M solution of MX is added dropwise to a mixture containing A–, B–, C– and D– ions then t…
Ksp of Mg (OH)₂ is 1 × 10–12. 0.01 M Mg (OH)₂ will be precipitating at the limiting pH :
Calculate the concentration of H⁺ ion in mol/L of 0.010M solution of NH₄Cl? (Kb = 1.8 × 10–6)
The correct order of increasing [H₃O⁺] in the following aqueous solution is:
H S aq H aq HS aq ;K 9.5 10 x HS aq H aq S aq ;K 1.0 10 x Given the equilibrium constants provided what is the equilibrium constant for the reaction: S (aq) 2H (aq) H S(aq) K = ?
How many milliliters (mL) of a 0.0500 M NaOH (a strong base) solution should be added to 1.00 L of 0.100 M H₃PO₄, solution to produce a buffer of pH = 2.00 ? For H₃PO₄, a K = 6.67 × 10–3 Given: H PO …
How many milliliters of 0.250 M NH₄Cl would have to be added to 450 mL of 0.350 M KOH in order to produce a buffer solution with a pH of 9.10? (Kb(NH₃) = 1.8 × 10–5)
Which pair of reagents, mixed in the appropriate proportion, could make a buffer in pH 3-4 range ?
A buffer is prepared by adding 0.30 mol CH₃COONa to 2.0 L of a 0.10 M CH₃COOH solution. Calculate the eq K /c (x y) eq K c/(xy) 1/(x y) x y 1 x y eq K /c x y eq K /xyc pH after 0.030 mol HCl are added t…
The pH of 10–5 M HCl solution if 1 ml of it is diluted to 1000 ml is :
When one drop of a concentrated HCl is added to 1 L of pure water at 25ºC, the pH drops suddenly from 7 to 4. When the second drop of the same acid is added, the pH of the solution further drops to about
A student dissolved 0.100 mol of an unknown monoprotic acid, HA, in sufficient water to make 1.00 L of solution. She measured the pH of the solution as pH = 2.60. Of the following, the acid HA is
For a “c molar” concentrated solution of a weak electrolyte AxBy, the degree of dissociation is given as (a) (b) (c) (d)
What is the equilibrium [OH–] in 0.1413 M H₂CO₃ ? H CO H O H O HCO (Ka = 4.30 ×10–7)
A mixture of weak acid is 0.1 M in HCOOH a K 1.8 10 x and 0.1 M in HOCN a K 3.1 10 x Hence, [H O ] is
The equilibrium constant for this reaction is approximately 10–3. HPO (aq.) HCO (aq.) H PO (aq.) CO (aq.) Which is the strongest conjugate base in this reaction? (a) HPO (aq.) (b) HCO (aq.) (c) H PO (aq.) (d) CO (aq.)
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: 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: Increasing pressure on pure water decreases its freezing point. Reason: Density of water is maximum at 4° C.
Assertion: Anhydrous BaO₂ (barium peroxide) is used for preparing H₂O₂. Reason: Hydrated BaO₂ is not available.
Choose the correct statement about the given figures.
What is the volume of “20 volume H₂O₂” required to get 5000 cm3 of oxygen at STP ?
The volume of oxygen liberated from 15 mL of 20 volume H₂O₂ is
A commercial sample of hydrogen peroxide is labelled as 10 volume. Its percentage strength is nearly