271. Washing soda is chemically represented by Na₂CO₃ Na₂CO₃.H₂O Na₂CO₃.10H₂O NaHCO₃ ✅ The correct answer is option C.
272. Multistage catalytic converter is not used in the Conversion of SO₂ to SO₃ NH₃ synthesis reaction Both A & B Neither A nor B ✅ The correct answer is option B.
273. Flexible foam (for mattresses) is usually made of PVC Silicone Polyurethanes Polyamides ✅ The correct answer is option C.
274. Systemic insecticides Are absorbed throughout the plant Kill insects following external bodily contact Are stomach poisons Emit poisonous vapour ✅ The correct answer is option A.
275. Blue vitriol is chemically Copper sulphate Ferrous sulphate Copper nitrate Aluminium sulphate ✅ The correct answer is option A.
276. A bio-catalyst produced by living cells which acts independent of the cell is called a/an Substrate Enzyme Nutrient None of these ✅ The correct answer is option B.
278. Epoxy resin Is a good adhesive Is an elastomer Cannot be used for surface coatings Is a polyester ✅ The correct answer is option A.
279. Nickel is not used as a catalyst in the __________ reaction. Shift conversion Oil hydrogenation Steaming reforming of naphtha Ammonia cracking/dissociation ✅ The correct answer is option A.
280. Varnish does not contain Pigment Thinner Dryer Anti-skimming agent ✅ The correct answer is option A.