Answer: Aluminium oxide and zinc oxide are amphoteric oxides; they react with dilute hydrochloric acid to form corresponding chlorides and with aqueous sodium hydroxide to form soluble aluminates or zincates. Calcium oxide is a basic oxide; it reacts with dilute hydrochloric acid but not with sodiumRead more
Answer: Aluminium oxide and zinc oxide are amphoteric oxides; they react with dilute hydrochloric acid to form corresponding chlorides and with aqueous sodium hydroxide to form soluble aluminates or zincates. Calcium oxide is a basic oxide; it reacts with dilute hydrochloric acid but not with sodium hydroxide. Sulphur dioxide is an acidic oxide; it does not react with hydrochloric acid but reacts with bases like sodium hydroxide to give sulphites/bisulphites, so statement IV is incorrect here.
Answer: When an iron nail is placed in aqueous copper(II) sulphate (tube P), iron, being more reactive, displaces copper ions; copper is deposited as reddish-brown metal on the nail and iron goes into solution as Fe²⁺. In aqueous silver nitrate (tube Q), iron similarly displaces silver; silver metalRead more
Answer: When an iron nail is placed in aqueous copper(II) sulphate (tube P), iron, being more reactive, displaces copper ions; copper is deposited as reddish-brown metal on the nail and iron goes into solution as Fe²⁺. In aqueous silver nitrate (tube Q), iron similarly displaces silver; silver metal plates the nail producing a silver coating while iron salts form in the solution. Thus both tubes show displacement reactions, with copper and silver metals deposited respectively during the experiment period.
Sodium hydroxide will give the highest pH when equal volumes are dissolved because it is a strong base that dissociates completely to yield a high concentration of hydroxide ions. Magnesium hydroxide, although a base, is sparingly soluble so it produces far fewer OH⁻ ions in solution. Sulphuric acidRead more
Sodium hydroxide will give the highest pH when equal volumes are dissolved because it is a strong base that dissociates completely to yield a high concentration of hydroxide ions. Magnesium hydroxide, although a base, is sparingly soluble so it produces far fewer OH⁻ ions in solution. Sulphuric acid is a strong acid and acetic acid is a weak acid; both produce H⁺ ions and lower pH values, so their solutions will be much less alkaline than NaOH commonly. Correct option – D.
Passing excess carbon dioxide through lime water initially produces a white precipitate of insoluble calcium carbonate, causing milkiness. On continued bubbling, carbon dioxide dissolves in water to form carbonic acid which reacts with calcium carbonate to yield calcium bicarbonate. Calcium bicarbonRead more
Passing excess carbon dioxide through lime water initially produces a white precipitate of insoluble calcium carbonate, causing milkiness. On continued bubbling, carbon dioxide dissolves in water to form carbonic acid which reacts with calcium carbonate to yield calcium bicarbonate. Calcium bicarbonate is soluble in water, so the precipitate dissolves and the milky appearance disappears. Therefore insoluble calcium carbonate converts to a soluble bicarbonate on excess CO₂, explaining the clearing of lime water in this common laboratory demonstration today. Correct option – B.
When aqueous barium chloride (BaCl₂) reacts with aqueous sodium sulphate (Na₂SO₄), a double displacement reaction occurs producing insoluble barium sulphate (BaSO₄) as a white precipitate and sodium chloride (NaCl) in the aqueous phase. The ionic equation shows Ba²⁺ combining with SO₄²⁻ to form BaSORead more
When aqueous barium chloride (BaCl₂) reacts with aqueous sodium sulphate (Na₂SO₄), a double displacement reaction occurs producing insoluble barium sulphate (BaSO₄) as a white precipitate and sodium chloride (NaCl) in the aqueous phase. The ionic equation shows Ba²⁺ combining with SO₄²⁻ to form BaSO₄(s), while Na⁺ and Cl⁻ remain dissolved as spectator ions producing NaCl(aq). Therefore the aqueous solution after reaction contains sodium chloride, and barium sulphate separates out as a solid under normal laboratory conditions at room. Correct option – D.
Four statements about the reactions of oxides with dilute hydrochloric acid and aqueous sodium hydroxide are listed. I. Aluminium oxide reacts with both dilute hydrochloric acid and aqueous sodium hydroxide. II. Calcium oxide reacts with dilute hydrochloric acid and aqueous sodium hydroxide. III. Zinc oxide reacts with both dilute hydrochloric acid and aqueous sodium hydroxide. IV. Sulphur dioxide does not react with either dilute hydrochloric acid or aqueous sodium hydroxide. Which statements are correct?
Answer: Aluminium oxide and zinc oxide are amphoteric oxides; they react with dilute hydrochloric acid to form corresponding chlorides and with aqueous sodium hydroxide to form soluble aluminates or zincates. Calcium oxide is a basic oxide; it reacts with dilute hydrochloric acid but not with sodiumRead more
Answer: Aluminium oxide and zinc oxide are amphoteric oxides; they react with dilute hydrochloric acid to form corresponding chlorides and with aqueous sodium hydroxide to form soluble aluminates or zincates. Calcium oxide is a basic oxide; it reacts with dilute hydrochloric acid but not with sodium hydroxide. Sulphur dioxide is an acidic oxide; it does not react with hydrochloric acid but reacts with bases like sodium hydroxide to give sulphites/bisulphites, so statement IV is incorrect here.
See lessAn iron nail is added to each of the two test tubes ‘P’ and ‘Q’ containing aqueous copper (II) sulphate, and aqueous silver nitrate respectively. Which of the following observation is correct?
Answer: When an iron nail is placed in aqueous copper(II) sulphate (tube P), iron, being more reactive, displaces copper ions; copper is deposited as reddish-brown metal on the nail and iron goes into solution as Fe²⁺. In aqueous silver nitrate (tube Q), iron similarly displaces silver; silver metalRead more
Answer: When an iron nail is placed in aqueous copper(II) sulphate (tube P), iron, being more reactive, displaces copper ions; copper is deposited as reddish-brown metal on the nail and iron goes into solution as Fe²⁺. In aqueous silver nitrate (tube Q), iron similarly displaces silver; silver metal plates the nail producing a silver coating while iron salts form in the solution. Thus both tubes show displacement reactions, with copper and silver metals deposited respectively during the experiment period.
See lessWhich of the following substances when dissolved in equal volume of water, will have the highest pH value?
Sodium hydroxide will give the highest pH when equal volumes are dissolved because it is a strong base that dissociates completely to yield a high concentration of hydroxide ions. Magnesium hydroxide, although a base, is sparingly soluble so it produces far fewer OH⁻ ions in solution. Sulphuric acidRead more
Sodium hydroxide will give the highest pH when equal volumes are dissolved because it is a strong base that dissociates completely to yield a high concentration of hydroxide ions. Magnesium hydroxide, although a base, is sparingly soluble so it produces far fewer OH⁻ ions in solution. Sulphuric acid is a strong acid and acetic acid is a weak acid; both produce H⁺ ions and lower pH values, so their solutions will be much less alkaline than NaOH commonly. Correct option – D.
See lessWhen excess of carbon dioxide is passed through lime water, the milkiness disappears because
Passing excess carbon dioxide through lime water initially produces a white precipitate of insoluble calcium carbonate, causing milkiness. On continued bubbling, carbon dioxide dissolves in water to form carbonic acid which reacts with calcium carbonate to yield calcium bicarbonate. Calcium bicarbonRead more
Passing excess carbon dioxide through lime water initially produces a white precipitate of insoluble calcium carbonate, causing milkiness. On continued bubbling, carbon dioxide dissolves in water to form carbonic acid which reacts with calcium carbonate to yield calcium bicarbonate. Calcium bicarbonate is soluble in water, so the precipitate dissolves and the milky appearance disappears. Therefore insoluble calcium carbonate converts to a soluble bicarbonate on excess CO₂, explaining the clearing of lime water in this common laboratory demonstration today. Correct option – B.
See lessIn the reaction of aqueous solution of barium chloride with aqueous solution of sodium sulphate, the aqueous solution formed will be:
When aqueous barium chloride (BaCl₂) reacts with aqueous sodium sulphate (Na₂SO₄), a double displacement reaction occurs producing insoluble barium sulphate (BaSO₄) as a white precipitate and sodium chloride (NaCl) in the aqueous phase. The ionic equation shows Ba²⁺ combining with SO₄²⁻ to form BaSORead more
When aqueous barium chloride (BaCl₂) reacts with aqueous sodium sulphate (Na₂SO₄), a double displacement reaction occurs producing insoluble barium sulphate (BaSO₄) as a white precipitate and sodium chloride (NaCl) in the aqueous phase. The ionic equation shows Ba²⁺ combining with SO₄²⁻ to form BaSO₄(s), while Na⁺ and Cl⁻ remain dissolved as spectator ions producing NaCl(aq). Therefore the aqueous solution after reaction contains sodium chloride, and barium sulphate separates out as a solid under normal laboratory conditions at room. Correct option – D.
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