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.
The assertion is incorrect because members of a homologous series differ by a fixed CH₂ unit and have similar functional groups and general formula. C₄H₁₀ is an alkane (saturated) with formula CnH2n+2, whereas C₄H₈ is an alkene and C₄H₆ an alkyne/diene — both unsaturated and belonging to different hRead more
The assertion is incorrect because members of a homologous series differ by a fixed CH₂ unit and have similar functional groups and general formula. C₄H₁₀ is an alkane (saturated) with formula CnH2n+2, whereas C₄H₈ is an alkene and C₄H₆ an alkyne/diene — both unsaturated and belonging to different homologous series. The reason statement R is true: the listed compounds (C₄H₈, C₄H₆, C₃H₄, C₃H₆, C₂H₄, C₂H₂) are examples of unsaturated hydrocarbons. Therefore, option D is the correct choice here.
An 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.
See lessAssertion (A): C4H8, C4H6 and C4H10 are members of the same homologous series Reason (R): C4H8, C4H6, C3H4, C3H6, C2H4, C2H2 are unsaturated hydrocarbons.
The assertion is incorrect because members of a homologous series differ by a fixed CH₂ unit and have similar functional groups and general formula. C₄H₁₀ is an alkane (saturated) with formula CnH2n+2, whereas C₄H₈ is an alkene and C₄H₆ an alkyne/diene — both unsaturated and belonging to different hRead more
The assertion is incorrect because members of a homologous series differ by a fixed CH₂ unit and have similar functional groups and general formula. C₄H₁₀ is an alkane (saturated) with formula CnH2n+2, whereas C₄H₈ is an alkene and C₄H₆ an alkyne/diene — both unsaturated and belonging to different homologous series. The reason statement R is true: the listed compounds (C₄H₈, C₄H₆, C₃H₄, C₃H₆, C₂H₄, C₂H₂) are examples of unsaturated hydrocarbons. Therefore, option D is the correct choice here.
See less