Q- Photochemical smog normally does not contain
(a) Chlorofluorocarbons
(b) Peroxyacetyl nitrate
(c) Ozone
(d) Acrolein
Answer: (a)
Q- Depletion of the ozone layer is caused due to
(a) Ferrocene
(b) Fullerenes
(c) Freons
(d) Polyhalogens
Answer: (c)
Q- Find the incorrect statement
(a) BOD value of clean water is less than 5 ppm
(b) Drinking water pH should be between 5.5-9.5
(c) carbon, sulphur and nitrogen oxides are the most widespread air pollutants
(d) dissolved oxygen concentration below 5 ppm is ideal for the growth of fish
Answer: (d)
Q- Find the secondary pollutant among these
(a) PAN
(b) N2O
(c) SO2
(d) CO2
Answer: (a)
Q- The reaction responsible for the radiant energy of the Sun is
(a) nuclear fission
(b) nuclear fusion
(c) chemical reaction
(d) combustion
Answer: (b)
Q- Alum’s capacity to purify water is due to
(a) softens hard water
(b) pathogenic bacteria get destroyed
(c) impurities’ coagulation
(d) it improves taste
Answer: (c)
Q- The coldest region of the atmosphere
(a) Troposphere
(b) Thermosphere
(c) Stratosphere
(d) Mesosphere
Answer: (d)
Q- Which of the oxide of nitrogen is not a common pollutant?
(a) N2O5
(b) N2O
(c) NO
(d) NO2
Answer: (a)
Q- The compound essential for the process of photosynthesis has this element
(a) Ca
(b) Ba
(c) Fe
(d) Mg
Answer: (d)
Q- In the air, N2 and O2 occur naturally but they do not react to form oxides of nitrogen because
(a) oxides of nitrogen are unstable
(b) catalyst is required for the reaction
(c) the reaction is endothermic
(d) N2 and O2 do not react with each other
Answer: (c)
Q- Which is the best-suited method for the separation of para and ortho-nitrophenols from 1:1 mixture?
(a) crystallisation
(b) chromatography
(c) sublimation
(d) steam distillation
Answer: (d)
Q- Find the incorrect statement for a nucleophile
(a) A nucleophile is a Lewis acid
(b) Nucleophiles do not seek electron
(c) Ammonia is a nucleophile
(d) Nucleophiles attack low electron density sites
Answer: (a)
Q- Which among the following is the most deactivating meta-directing group in aromatic substitution reaction?
(a) -COOH
(b) -SO3H
(c) -NO2
(d) -CN
Answer: (c)
Q- Ammonia evolved from 0.75 g of the soil sample in the Kjeldahl’s method for nitrogen estimation, neutralises 10 ml of 1M H2SO4. Find the percentage of nitrogen present in the soil
(a) 35.33
(b) 37.33
(c) 43.33
(d) 45.33
Answer: (b)
Q- The correct order of increasing nucleophilicity is
(a) Cl– < Br– < I–
(b) Br– < Cl– < I–
(c) I– < Br– < Cl–
(d) I– < Cl– < Br–
Answer: (a)
Q- Homologous series of alkanols have a general formula
(a) CnH2nO2
(b) CnH2nO
(c) CnH2n+1O
(d) CnH2n+2O
Answer: (d)
Q- Find the compound which undergoes nucleophilic substitution reaction exclusively by an SN1 mechanism
(a) Benzyl chloride
(b) Chlorobenzene
(c) Ethyl chloride
(d) Isopropyl chloride
Answer: (a)
Q- Which of the following methods is best suited for the separation of a mixture containing naphthalene and benzoic acid
(a) Crystallisation
(b) Chromatography
(c) Sublimation
(d) Distillation
Answer: (c)
Q- How many structural isomers are possible if one hydrogen in diphenylmethane is replaced by chlorine?
(a) 8
(b) 4
(c) 7
(d) 6
Answer: (b)
Q- Why do we boil the extract with conc. HNO3 in Lassaigne’s test for halogens?
(a) to increase the concentration of NO3– ions
(b) to increase the solubility product of AgCl
(c) it increases the precipitation of AgCl
(d) for the decomposition of Na2S and NaCN formed
Answer: (d)
