Initial volume (V₁ ) = 273 cm³

Initial pressure (P₁) = 1 atm = 760 mm Hg

Initial temperature (T₁) = 273 K (which is 0°C)

Final pressure (P₂) = 76 mm Hg

Final temperature (T₂) = 273°C = 546 K

Apply the Combined Gas Law: P_1V_1\\over T_1=P_2V_2\\over T_2

⇒ 760 × 273\\over 273=76 × V_2\\over 546

⇒ V₂ =760 × 273 ×  546\\over 273 × 76

⇒ V₂ = 5460 cm³

Thus, the volume of the gas at 76 mm Hg pressure and 273°C is approximately 5460 cm³.

The functional group present in ethyl alcohol (ethanol) is the hydroxyl group (−OH)

A superconductor is a material that can conduct electricity with zero electrical resistance.

Example: Mercury below 4.2 K, and lead below 7.25 are superconductors.

UV rays are used to kill microorganisms in water and on surfaces.

Gamma rays are used in cancer treatment and medical imaging.

One ore of iron is hematite. Its chemical formula is Fe₂O₃.

Polymerisation of ethylene: Ethylene is liquified at high pressure (1500-2000 atm). In the presence of catalysts such as peroxide, oxygen or chromium oxide and at temperatures 150℃-200℃, a large number of ethylene molecules join to form a white solid called polyethylene or polythene.

nC₂​H₄​→ (C₂​H₄​​)_n

d. CO₂

Explanation: Although CO₂ is a greenhouse gas and contributes to global warming, it does not directly participate in the depletion of the ozone layer.

b. 0.5RT

Explanation:

At STP (Standard Temperature and Pressure), the conditions are:

• Temperature (T) = 273 K
• Pressure (P) = 1 atm
• 1 mole of an ideal gas occupies a volume (V) of 22.4 liters.

Calculation of mole: n = 11.2/22.4 = 0.5

From the ideal gas equation:

PV =nRT

or, PV = 0.5 RT

a. 448 L

Explanation:

Since 1 mole of CH₄ requires 2 moles of O₂,

∴ 10 moles of CH₄ will require = 10 × 2 = 20 moles of O₂

Volume of 20 moles of O₂ = 20 × 22.4 = 448 L

b. Diamond

Explanation: Diamond has the highest thermal conductivity of any known material. Its structure allows for extremely efficient heat transfer.

c. r > v

Explanation: When light passes from one medium to another (air to prism in this case), the amount of bending (refraction) depends on the wavelength of the light.

The refractive index (μ) of a medium is higher for shorter wavelengths (violet) and lower for longer wavelengths (red).

Since the refractive index for violet light is higher, it bends more than red light when entering the prism. This means:

• r (angle of refraction for red light) will be greater than v (angle of refraction for violet light) because violet light bends more.

b. 180°

Explanation: At the center of curvature of a concave mirror, light rays hit the mirror perpendicularly and reflect back along the same path. The angle of deviation is the angle between the incident and reflected ray, which in this case is 180°.