Ncert Solutions Chemistry Class 12th

(i) Ca²⁺ + 2e^- → Ca
⇒ Here, 1 mole of Ca, i.e., 40g of Ca requires = 2 F electricity (F if Faraday)
∴ 20g of Ca requires = 20X2/40
= 1 F of electricity
Electricity in terms of Faraday required to produce 20.0 g of Ca from molten CaCl₂ is 1 F of electricity.

(ii) Al³⁺ + 3e^-  → Al
⇒ 1 mole of Al, i.e., 27g of Al requires = 3 F electricity (F if Faraday)
∴ 40.0 g of Al will require = 3/27 X 40
= 4.44 F of electricity
Electricity in terms of Faraday required to produce 40.0 g of Al from molten Al₂O₃ is 4.44 F of electricit

14.13 

The condensation of the hydroxyl group of two monosaccharides to form a link between them is called glycosidic linkage. In other words, it refers to linkage developed between two different monosaccharide units through an oxygen atom by the loss of a water molecule. For example, in a sucrose molecule, two monosaccharide units, α-glucose and β–fructose, are joined together by a glycosidic linkage.

The electrode reaction is given as,  

Al³⁺ (aq) + 3e^- → Al (s)

∴ The quantity of charge required for the reduction of 1 mol of Al³⁺ = 3F

= 3*96487 C

= 289461 C

The electrode reaction is given as,

Cu²⁺ (aq) + 2e^- → Cu (s)

∴ The quantity of charge required for the reduction of 1 mol of Cu²⁺ = 2F

= 2*96487 C

= 192974 C

The electrode reaction is given as, MnO₄→ Mn²⁺

i.e., Mn⁷⁺ + 5e ^- → Mn²⁺

∴ The quantity of charge required for the reduction of 1 mol of Mn⁷⁺ = 5F

= 5*96487 C

= 482435 C

14.12 

i. Ribose, 2-deoxyribose, galactose, and fructose are

Monosaccharides are the simplest units of carbohydrates which cannot be hydrolyzed into simpler compounds.

ii. Maltose and lactose are

A disaccharide is a carbohydrate that is formed when two monosaccharides are joined together and a molecule of water is removed from the structure. Lactose is a disaccharide formed from the combination of galactose and glucose.

Given -

Molarity, C = 0.00241 M

Conductivity, κ = 7.896 * 10^–5 S cm^–1

Molar conductivity? _m =?

? ⁰_m for acetic acid = 390.5 S cm²mol^–1

Molar conductivity? _m = k/c X 1000 S cm² mol^-1

 = 7.896 X 10^–5 S cm^–1X 1000 cm³ L^-1  / 0.00241 mol L^-1

∴? _m = 32.76 S cm² mol^-1

To calculate the dissociation constant, K_a, we use

K_a =  → Equation 1

Here, we need to find the value of α (degree of dissociation), by the formula,

The molar conductivity? _m is 32.76 S cm² mol^-1 and the dissociation constant, K_a is 1.86*10^-5

14.10 

All those carbohydrates which reduce Fehling's solution to red precipitate of Cu₂O or Tollen's reagent to metallic Ag is called reducing sugars. All monosaccharides (both aldoses and ketoses) and disaccharides except Sucrose are reducing sugars.

? ⁰ R = Intercept on the? axis = 124.0 S cm² mol^-1, which is obtained by extrapolation to zero concentration.