19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Silver is extracted from its native ore by:
Which of the following reactions does not occur in Bessemer converter in the extraction of copper from chalcopyrites?
Refining of impure copper with zinc impurity is to be done by electrolysis using electrodes as Cathode Anode
The methods chiefly used for the extraction of lead and tin from their ores are respective
Which of the following pair of ores cannot be converted into corresponding metals by pyrometallurgy?
Formation of metallic copper from the sulphide ore in the commercial metallurgical process involves. (a) Cu S⁺ O Cu O+SO ; Cu O+C 2Cu+CO → → (b) Cu S O Cu O SO ; 2Cu O Cu S 6Cu SO → → (c) Cu S 2O CuSO ; CuSO Cu S 3Cu …
Which of the following factors is of no significance for roasting sulphide ores to the oxides and not subjecting the sulphide ores to carbon reduction directly
Select correct statement:
Boron can be obtained by various methods but not by:
Assertion: In the electrolytic reduction of Al₂O₃, cryolite is used. Reason: Cryolite is an ore of aluminium.
The chemical composition of ‘slag’ formed during the smelting process in the extraction of copper is
Assertion: All the ores are mineral. Reason: Ores contains metals in combined state
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.