When a substance A reacts with water, it produces a combustible gas B and a solution of substance C in water. D reacts with this solution C and produces the same gas B on warming. D can also produce gas B on reaction with dilute H2SO4. A imparts a deep golden yellow colour to smokeless flame. A, B, C and D respectively are
When a substance A reacts with water, it produces a combustible gas B and a solution of substance C in water. D reacts with this solution C and produces the same gas B on warming. D can also produce gas B on reaction with dilute H2SO4. A imparts a deep golden yellow colour to smokeless flame. A, B, C and D respectively are
The correct option is A Na, H2, NaOH, Zn
Alkali on reacting with water, liberate hydrogen and forms respective hydroxide. CaC2 on reacting with water form calcium hydroxide and acetylene which is also combustible.
Potassium imparts lilac colour to flame test
Ca imparts orange-red colour to flame test
Only sodium imparts a deep golden yellow colour to fame test.
Hence the correct option is (a).
Water:
1. Due to the presence of lone pairs, the geometry of water is distorted
2. The geometry of the molecule is regarded as angular or bent
3. H-O-H bond angle 104.5o is less than the normal tetrahedral angle 109.5o
4. Each O-H bond is polar. E.N. of O (3.5) > E.N. of H (2.1)
High freezing point, high boiling point, high heat of vapourisation and high heat of fusion. as compared to H2S to H2Te
Water has a higher specific heat, thermal conductivity, surface tension, dipole moment and dielectric constant. In comparison to other liquids. Hence, the density of ice is less than that of water and ice floats over water
Physical properties :
One of the properties of water that makes it suitable for organism to survive during differing weather condition is that, water expands as it freezes. Here we fill a glass bottle up to brim and place a coin on its loosely held cap. As soon as water starts freezing, we observe that coin has gradually started to fall. After complete freezing we observe that coin has fallen and bottle start cracking due to expansion of water on freezing. Due to this volume increase density of ice is less than that of water hence ice floats on water.
Triple point - At 273 K water is in equilibrium with ice and vapour.
Dissociation of water:
Water is quite stable and does not dissociate into its elements even at high temperatures
Amphoteric nature of water:
H2O(l)+NH3(aq)⇌OH−(aq)+NH+4(aq)
H2O(l)+H2S(aq)⇌H3O+(aq)+HS−(aq)
H2O(l)+H2O(aq)⇌H3O+(aq)+OH−(aq)
Acid 1 base 2 conjugate acid conjugate base
Oxidizing and reducing nature:
2Na+H2O⟶2NaOH+H2
2F2+H2O⟶4HF+O2
Hydrolytic reactions:
Hydrolyses many oxides, halides, hydrides, carbides, nitrides, phosphides, carbonates, etc., to give an acid or a base or both
H2O+SO2⟶H2SO3
Mg3N2+6H2O⟶3Mg(OH)2+2NH3
CaH2+2H2O⟶Ca(OH)2+2H2
SiCl4+4H2O⟶Si(OH)4+4HCl
Ca3P2+6H2O⟶3Ca(OH)2+2PH3
Water forms three types of hydrates with metal :
a. Compounds in which water molecules are coordinated to the metal ion (complex compounds)
E.g. [Fe(H2O)6]Cl3
b. Compound in which water molecules may be hydrogen bonded to oxygen
c. In some compounds, water molecules occupy the interstitial sites in the crystal lattice
Alkali on reacting with water, liberate hydrogen and forms respective hydroxide. CaC2 on reacting with water form calcium hydroxide and acetylene which is also combustible.
Potassium imparts lilac colour to flame test
Ca imparts orange-red colour to flame test
Only sodium imparts a deep golden yellow colour to fame test.
Hence the correct option is (a).
Water:
1. Due to the presence of lone pairs, the geometry of water is distorted
2. The geometry of the molecule is regarded as angular or bent
3. H-O-H bond angle 104.5o is less than the normal tetrahedral angle 109.5o
4. Each O-H bond is polar. E.N. of O (3.5) > E.N. of H (2.1)
High freezing point, high boiling point, high heat of vapourisation and high heat of fusion. as compared to H2S to H2Te
Water has a higher specific heat, thermal conductivity, surface tension, dipole moment and dielectric constant. In comparison to other liquids. Hence, the density of ice is less than that of water and ice floats over water
Physical properties :
One of the properties of water that makes it suitable for organism to survive during differing weather condition is that, water expands as it freezes. Here we fill a glass bottle up to brim and place a coin on its loosely held cap. As soon as water starts freezing, we observe that coin has gradually started to fall. After complete freezing we observe that coin has fallen and bottle start cracking due to expansion of water on freezing. Due to this volume increase density of ice is less than that of water hence ice floats on water.
Triple point - At 273 K water is in equilibrium with ice and vapour.
Dissociation of water:
Water is quite stable and does not dissociate into its elements even at high temperatures
Amphoteric nature of water:
H2O(l)+NH3(aq)⇌OH−(aq)+NH+4(aq)
H2O(l)+H2S(aq)⇌H3O+(aq)+HS−(aq)
H2O(l)+H2O(aq)⇌H3O+(aq)+OH−(aq)
Acid 1 base 2 conjugate acid conjugate base
Oxidizing and reducing nature:
2Na+H2O⟶2NaOH+H2
2F2+H2O⟶4HF+O2
Hydrolytic reactions:
Hydrolyses many oxides, halides, hydrides, carbides, nitrides, phosphides, carbonates, etc., to give an acid or a base or both
H2O+SO2⟶H2SO3
Mg3N2+6H2O⟶3Mg(OH)2+2NH3
CaH2+2H2O⟶Ca(OH)2+2H2
SiCl4+4H2O⟶Si(OH)4+4HCl
Ca3P2+6H2O⟶3Ca(OH)2+2PH3
Water forms three types of hydrates with metal :
a. Compounds in which water molecules are coordinated to the metal ion (complex compounds)
E.g. [Fe(H2O)6]Cl3
b. Compound in which water molecules may be hydrogen bonded to oxygen
c. In some compounds, water molecules occupy the interstitial sites in the crystal lattice
