51.

The example of thermosetting and thermoplastic polymer respectively is

• polystyrene, polyvinylchloride

• bakelite, polystyrene

• polyethene, polyacredonitrile

• polystyrene, urea-formaldehyde resin

Which of the following is not a 'greenhouse gas'?

• SO₂

• CFC

• CH₄

• N₂O

Which of the following is the weakest Lewis Base?

• OH^-

• H^-

• HCO_3^- 

• Cl^-

The cooking gas is mainly a mixture of the following two gases

• methane and ethane

• ethane and propane

• propane and butane

• butane and pentane

Electronic configuration of Cr is

• 3d⁵ 4s¹

• 3d⁶ 4s⁰

• 3d⁴ 4s²

• 3d⁵ 4s⁰

Producer gas is

• Mixture of CO and H₂

• Mixture of CO₂ and H₂

• Mixture of CO₂ and Cl₂

• Mixture of CO and N₂

Which alloy is not possible?

• Cu- Zn

• Pb- Zn

• Cu- Au

• Cu- Ag

What is the color of the precipitate which is formed when aqueous solutions of sodium sulphate and barium chloride are mixed?

• Yellow

• White

• Green

• Orange

Which one is least reactive?

• Iron

• Copper

• Silver

• Gold

Which is not obtained by the destructive distillation of coal?

• Coal gas

• Petroleum

• Ammonia Liquor

• Coal tar