Explanation

• A Reynolds number of 1500 indicates laminar flow.
• In pipe flow, Re < 2000 is generally considered laminar.
• In laminar flow, fluid particles move in smooth, parallel layers with little mixing.
• Oil commonly shows laminar behavior because of its higher viscosity.

Last verified on 26-06-2026

Explanation

• Radiative heat emission increases sixteen times when the absolute temperature doubles.
• According to Stefan-Boltzmann law, heat radiation is proportional to the fourth power of absolute temperature (T⁴).
• If temperature becomes 2T, emission becomes (2T)⁴ = 16T⁴.
• This applies to heat emitted by hot surfaces.

Last verified on 26-06-2026

Explanation

• Conduction is the main mode of heat transfer that makes a metal spoon hot in hot tea.
• Heat moves from the hot tea to the spoon through direct contact.
• Metals are good conductors of heat because they have free-moving electrons.
• Heat flows from a region of higher temperature to lower temperature.

Last verified on 26-06-2026

Explanation

Reaction: NH₃ + HNO₃ → NH₄NO₃  

Mole ratio is 1:1  

Molar masses: NH₃ = 17 g/mol, NH₄NO₃ = 80 g/mol  

80 kg NH₄NO₃ = 80/80 = 1 kmol  

So you need 1 kmol NH₃  

Mass NH₃ = 1 kmol × 17 kg/kmol = 17 kg

Last verified on 26-06-2026

Explanation

• In the Haber process, 4 moles of gas (N₂ + 3H₂) produce 2 moles of NH₃, so high pressure shifts equilibrium toward ammonia.
• High pressure also increases the rate of reaction, making industrial production more efficient.
• Although compression requires more energy, the higher yield of ammonia justifies the cost.

Last verified on 26-06-2026

Explanation

• In the Contact process, vanadium pentoxide (V₂O₅) is used as a catalyst for converting SO₂ into SO₃.
• It increases the reaction rate without being consumed.
• It is preferred due to its efficiency and lower cost compared to platinum.

Last verified on 26-06-2026

Explanation

• Steam reforming is an endothermic reaction, so it requires heat.
• When temperature decreases, equilibrium shifts in the backward direction to produce more heat (toward reactants).
• Therefore, hydrogen production decreases.

Last verified on 26-06-2026

Explanation

• In distillation, the liquid with the lower boiling point evaporates first because it requires less heat to become vapor.
• The vapor is then cooled and collected as the more volatile component.
• Components with higher boiling points remain in the liquid phase longer.

Last verified on 26-06-2026

Explanation

• At 18°C, air reaches its dew point, so condensation starts.
• If cooling continues below 18°C, more water vapor changes into liquid water.
• Therefore, water vapor condenses continuously and moisture content decreases.

Last verified on 26-06-2026

Explanation

Relative volatility α = 1.05 means the two components have almost the same volatility.

Rule of thumb:  

• α >> 1 → easy separation, few trays  
• α ≈ 1 → difficult separation, needs many equilibrium stages + high reflux  
• α = 1 → no separation possible by distillation

Here α = 1.05 is very close to 1, so simple distillation won’t work well. You’d need many stages/plates and high energy.

Last verified on 25-06-2026