19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Assertion: Cryolite is used in electrolytic extraction of Al from alumina. Reason: It dissolves alumina.
Assertion: Thermite mixture Fe₂O³⁺ Al (powder) is used in the welding. Reason: Al is a good reductant.
Assertion: CuFeS₂ is concentrated by froth floatation method. Reason: CuFeS₂ is main ore of copper.
Assertion: Extraction of iron metal from iron oxide ore is carried out by heating with coke. Reason: The reaction, Fe O (s) Fe(s)+ O (g) → is a spontaneous process.
Assertion: Ores are generally converted into oxides, prior to reduction. Reason: Metal oxides can be easily reduced.
Assertion: In the extraction of Ag, complex Na [Ag (CN)₂] is reacted with Zn. Reason: Zn is d-block transition metal.
Assertion: In the electrolytic reduction of Al₂O₃, cryolite is used. Reason: Cryolite is an ore of aluminium.
Silver is extracted from its native ore by:
Which of the following is not correctly matched?
The metal ores [X] and [Y] are respectively:
Which of the following statements is correct about [Y]?
Assertion: Wrought iron is more malleable and ductile than steel. Reason: It contains slightly less percentage of carbon.
Consider the following reaction which proceeds predominantly forward HSO NH NH SO From the information given it is clear that (a) HSOis a stronger acid than NH.
The solubility of CaCO₃ is 7 mg/L. Calculate the solubility product of BaCO₃ from this information and from the fact that when Na₂CO₃ is added slowly to a solution containing equimolar concentration …
The solubility of AgCl is maximum in
The solubility of LiOH in a solution with pH = 8 is (Ksp = 1.8 × 10–12)
Assertion (A): pH of HCl solution is less than that of acetic acid of the same concentration. Reason (R): In equimolar solutions, the number of titrable protons present in HCl in less than that present in acetic…
Assertion: If HA and HB are two weak non-basic acids with Ka(HA) < Kb(HB), then, the aqueous solution of NaA will have higher pH than pH of aqueous solution of NaB of same concentration. Reason: Conjugate base of a…
Assertion: When aqueous, solution of CH₃COOAg is diluted, then its degree of hydrolysis increases. Reason: Silver acetate is the salt of weak acid and weak base; its degree of hydrolysis does not depend on th…
Assertion: When aqueous, solution of CH₃COONH₄ is diluted, then its degree of hydrolysis increases. Reason: Ammonium acetate is the salt of weak acid and weak base; its degree of hydrolysis does not de…
Assertion: Aqueous solution of ammonium carbonate is basic. Reason: Acidic or Basic nature of a salt solution of a salt of weak acid and weak base depends on Ka and Kb of the acid and base forming it.
Assertion: If a K of HA is 10–3 and a K of HB is 10 at 25ºC, pH of an aqueous solution of HB will be one unit greater than pH of equimolar solution of HA. Reason: For weak acids, both concentration and ionizat…
Assertion: pH of 10–8 M HCl lies between 6 and 7. Reason: For very dilute solutions of acids, H⁺ ion contribution from water is also taken into consideration.
Assertion: pH of water increases with an increase in temperature. Reason: Kw of water increases with increase in temperature.
Assertion: Addition of HCl(aq.) to HCOOH(aq.) decreases the ionization of HCOOH. Reason: Common ion effect of H⁺ ion, reduces the ionization of HCOOH.