Chemistry NCERT Exemplar Solutions Class 11th Chapter Nine

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H₂O (l)+NH₃ (aq) → OH^- (aq)+NH₄⁺ (aq)

H₂O (l)+H₂S (aq) → H₃O⁺ (aq)+HS^- (aq)

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2F₂ (g)+2H₂O → 4H⁺ (aq)+4F^- (aq)+O₂ (g)

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In water hybridisation of oxygen is sp³. Angle should be109^o (approx.) but due to LP - LP repulsion bond angle reduces to 104.5°.

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Because H₂SO₄ can activate the decomposition of H₂O₂.

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With soap, hard water generates scum/precipitate. Soap containing sodium stearate (C1₁₇H₃₅COONa) interacts with hard water to form calcium and magnesium stearate (Ca/Mg stearate). As a result, it is unsuitable for laundering. Because of the deposition of salts in the form of scale, it is also hazardous to boilers.

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Hydrogen peroxide is stored in wax lined bottles because decomposes slowly on exposure to light.

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Hydrogen peroxide cannot be concentrated by heating as it can cause bumps on heating. It can be extracted with water and concentrated to ~30% (by mass) by distillation under reduced pressure. It can be further concentrated to ~85% by careful distillation under low pressure. The remaining water can be frozen out to obtain pure H₂O₂.

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Water has a significantly higher boiling point than hydrogen sulphide because of the presence of strong hydrogen bonds between water molecules, which are absent in hydrogen sulphide due to the lower electronegativity of sulfur compared to oxygen; this means more energy is required to separate water molecules, resulting in a higher boiling point. 

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Water molecules are polar because in the gas phase water is a bent molecule with a bond angle of 104.5°, O-H bond length of 95.7 pm. Oxygen is more elsectronegative  (EN = 3.5 ) than hydrogen (EN= 2.1 ) hence, O-H bond is polar . In the water molecule, two polar O-H nonds area present which are held together at an angle of 104.5 . Due to the resultant of these two dipoles, water molecule is polar and has an dipole moment of 1.84 Debye.

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H₂O₂ decomposes slowly on exposure to light.

2H₂O₂→ 2H₂O+2O₂

In daily life it is used as a hair bleach and as a mild disinfectant. As an antiseptic it is sold in the market as perhydrol.