Top Chemistry MCQS

All Questions for: Top Chemistry MCQS

Question 301: Percentage of lead in lead pencil is________?

  • A 70
  • B 20
  • C 80
  • D Zero

Explanation: The correct answer to the question is: Zero

Question 302: Indicate the correct statement__________________?

  • A Cl2 is the strongest oxidizing agent
  • B Cl2 is insoluble in water
  • C I2 is a volatile solid
  • D Br2 is more reactive than Cl2

Explanation: The correct answer to the question is: I2 is a volatile solid

Question 303: The most powerful oxidizing agent among the halogens is__________________?

  • A F2
  • B Cl2
  • C Br2
  • D I2

Explanation: The correct answer to the question is: F2

Question 304: Acetal on acid hydrolysis generates__________________?

  • A Both A & B
  • B Ketone
  • C None of the above
  • D Alcohol

Explanation: The correct answer to the question is: Both A & B

Question 305: Air is a/an _________?

  • A  Mixture
  • B  Element
  • C  Electrolyte
  • D Compound

Explanation: The correct answer to the question is:  Mixture

Question 306: The valency of Carbon is _________?

  • A 2(Divalent)
  • B 1(univalent)
  • C 4(Tetravalent)
  • D 3(Trivalent)

Explanation: The correct answer to the question is: 4(Tetravalent)

Question 307: Ionic solids do not conduct the electrical current because:

  • A Strong covalent bonds are present in their structure
  • B Free electrons are less
  • C The coordination number of ion is very high
  • D Ions don’t have translatory motion

Explanation: The correct answer to the question is: Ions don’t have translatory motion

Question 308: Positron has __________charge.

  • A -ve
  • B +ve
  • C Neutral
  • D None of them

Explanation: The correct answer to the question is: +ve

Question 309: Reactivity due to pi-electrons is present in_________________?

  • A both B & C
  • B alkyne
  • C alkane
  • D alkene

Explanation: The correct answer to the question is: both B & C

Question 310: The energy of one mole of photons of radiation, whose frequency is 4×10 14 Hz, is ___________?

  • A 80.4 KJ
  • B 110.5 KJ
  • C 135.5 KJ
  • D 159.6kJ

Explanation: The correct answer to the question is: 159.6kJ

Question 311: When SO2 solution is passed over which of the following it turns green?

  • A SO3
  • B P2O5
  • C K2Cr2O7
  • D H2SO4

Explanation: The correct answer to the question is: K2Cr2O7

Question 312: 50% inversion of configuration of molecules take place in a___________________?

  • A SN2 – reaction
  • B E2 – reaction
  • C E1 – reaction
  • D SN1 – reaction

Explanation: The correct answer to the question is: SN1 – reaction

Question 313: What is the molecular formula for Nitric acid ________ ?

  • A HNO2
  • B HN2O2
  • C HNO3
  • D H2NO4

Explanation: The correct answer to the question is: HNO3

Question 314: The number of d-electrons in Fe2+ (Z = 26) is not equal to that of____________?

  • A  s-electrons in Mg(Z = 12)
  • B  p-electrons in CI(Z = 17)
  • C  d-electrons in Fe(Z = 26)
  • D p-electrons in Ne(Z = 10)

Explanation: The correct answer to the question is:  p-electrons in CI(Z = 17)

Question 315: Crystals of Na2CO3. 10H2O when exposed to air_________________?

  • A Gain water and become liquid
  • B Lose water and remain solid
  • C Remains unchanged
  • D Gain water and remain solid

Explanation: The correct answer to the question is: Lose water and remain solid

Question 316: Which of the following gases shows more ideal behaviour at 0°C___________?

  • A CH4
  • B H2
  • C NH3
  • D He

Explanation: The correct answer to the question is: He

Question 317: Charle’s Law was given by Jacques Charles in_______?

  • A 1880
  • B 1787
  • C 1885
  • D 1785

Explanation: The correct answer to the question is: 1787

Question 318: In melting of iron, which of the following reactions takes place in Bladt Furnace at 400°C- 600°C________?

  • A FeSiO3———> FeSiO3
  • B Fe2O3+ 3CO——–> 2Fe+ 3CO2
  • C 2FeS+3O2——–> 2Fe+ SO2
  • D CaO+ SiO2——> CaSiO3

Explanation: The correct answer to the question is: Fe2O3+ 3CO——–> 2Fe+ 3CO2

Question 319: Which Oxide of Manganese is amphoteric?

  • A MnO2
  • B Mn2O3
  • C Mn2O7
  • D MnO

Explanation: The correct answer to the question is: MnO2

Question 320: Alum is used by dyers of cloth:

  • A As water purifier
  • B fire proofing fabrics
  • C Softening of hard water
  • D As mordant

Explanation: The correct answer to the question is: As mordant

Question 321: In diaphragm cell level of brine in anode compartment is kept slightly higher which prevents_______________?

  • A Chlorine gas to mix
  • B All of the above
  • C Hydroxide ions to reach anode
  • D Cathode to decay

Explanation: The correct answer to the question is: Hydroxide ions to reach anode

Question 322: Chromatography is used to separate _________ ?

  • A Solution
  • B Molecules
  • C Atoms
  • D Mixtures

Explanation: The correct answer to the question is: Mixtures

Question 323: What will be the PH of  0.01M ammonium chloride solution containing 10 mol per liter of ammonium chloride (pkb=4.76)?

  • A 5.24
  • B 7.24
  • C 8.24
  • D 6.24

Explanation: The correct answer to the question is: 8.24

Question 324: Which of the following is not a use of silicon ?

  • A Hydraulic brakes
  • B Water repellent
  • C Lubricants
  • D Antifreeze

Explanation: The correct answer to the question is: Antifreeze

Question 325: The absolute value of charge on electron was determined by ________ ?

  • A Chadwick
  • B Robert Millikan
  • C Rutherford
  • D J.J.Thomson

Explanation: The correct answer to the question is: Robert Millikan

Question 326: Calculate % of N in KNO3__________?

  • A 14.34%
  • B 13.86%
  • C 18.56%
  • D None of these

Explanation: The correct answer to the question is: 13.86%

Question 327: Which of the following compounds will react with Tollens reagent ?

  • A CH3-CH-CH3
  • B CH3-COOH
  • C CH3-CO-CH2-CH3
  • D CH3-CHO

Explanation: The correct answer to the question is: CH3-CHO

Question 328: Tetrahydroborate ion is the source of_______________?

  • A H-
  • B proton
  • C H+
  • D both A & amp; B

Explanation: The correct answer to the question is: H-

Question 329: The molecular formula of Methane gas is___________?

  • A CO
  • B CH
  • C NH
  • D CH

Explanation: The correct answer to the question is: CH

Question 330: The Maximum mass of an atom is present in ___________?

  • A Nucleus
  • B Shell
  • C Orbit
  • D Energy levels

Explanation: The correct answer to the question is: Nucleus

Question 331: The octane number of zero is assigned to____________?

  • A  n-heptane
  • B  3-methyl octane
  • C  iso-octane
  • D 2-methyl octane

Explanation: The correct answer to the question is:  n-heptane

Question 332: Ethanol and methanol can be distinguished by a__________________?

  • A Benedicts test
  • B Iodoform test
  • C Tollens test
  • D Lucas test

Explanation: The correct answer to the question is: Iodoform test

Question 333: Acidic amino acids have________________?

  • A 2 carboxylic groups and 1 amino group
  • B 2 amino groups and 1 carboxylic group
  • C 1 amino and 1 carboxylic groups
  • D 2 amino and 2 carboxylic groups

Explanation: The correct answer to the question is: 2 carboxylic groups and 1 amino group

Question 334: Petra means ______ ?

  • A Rock
  • B Fuel
  • C Petrol
  • D Sediment

Explanation: The correct answer to the question is: Rock

Question 335: Oxidation of primary alcohol gives________________?

  • A Alkene then – COOH
  • B Ester
  • C ketone
  • D Aldehyde

Explanation: The correct answer to the question is: Aldehyde

Question 336: Which one is not a nucleophile ?

  • A NH3
  • B SCN-
  • C H3C+
  • D C2H5O-

Explanation: The correct answer to the question is: H3C+

Question 337: The PH of the 1.3 × 10-4 NH4Cl is__________?

  • A 1.3
  • B 4.0
  • C 3.886
  • D 2.886

Explanation: The correct answer to the question is: 3.886

Question 338: Example of cross linked polymer is ____________?

  • A bakelite
  • B Polyester
  • C PVC
  • D Nylon

Explanation: The correct answer to the question is: bakelite

Question 339: The best indicator for titrating HCl with NH4OH is: _________?

  • A methyl Orange
  • B phenopthalein
  • C litmus
  • D phenol red   

Explanation: The correct answer to the question is: methyl Orange

Question 340: Oxygen does not react with all except_________________?

  • A Alkali
  • B Water
  • C Metals
  • D Acid

Explanation: The correct answer to the question is: Metals

Question 341: Which of the following is more Basic in nature?

  • A 2° Alkyl ammine
  • B 1°Alkyl ammine
  • C 3° Alkyl ammine
  • D Ammonia

Explanation: The correct answer to the question is: 3° Alkyl ammine

Question 342: The density of a gas is 1.964 g dm-3 at 273 K and 76 cm Hg. The gas is _________?

  • A C2H4
  • B Xe
  • C CH4
  • D CO2

Explanation: The correct answer to the question is: CO2

Question 343: The element of group VIA which is a non-metal is________________?

  • A Te
  • B S
  • C Se
  • D Po

Explanation: The correct answer to the question is: S

Question 344: Which of the following is metasilicic acid ?

  • A H3SbO4
  • B H3AsO4
  • C H2SiO3
  • D H2SnO3

Explanation: The correct answer to the question is: H2SiO3

Question 345: Second ionization potential of alkali metals are very high due to_______________?

  • A being metals
  • B ns1 electronic configuration
  • C inert gas configurations
  • D being s-block elements

Explanation: The correct answer to the question is: inert gas configurations

Question 346: The structure of H2O2 is_______?

  • A Planar
  • B Linear
  • C Spherical
  • D Non- polar

Explanation: The correct answer to the question is: Non- polar

Question 347: Which of the following oxides of iodine is used for quantitative analysis of CO ?

  • A I2O5
  • B I4O2
  • C All are equally useful
  • D I2O4

Explanation: The correct answer to the question is: I2O5

Question 348: Cannizzaros reaction is not given by__________________?

  • A acetaldehyde
  • B benzaldehyde
  • C formaldehyde
  • D trimethyl acetaldehyde

Explanation: The correct answer to the question is: acetaldehyde

Question 349: Which is the strongest acid ?

  • A HCIO
  • B HCIO4
  • C HCIO2
  • D HCIO3

Explanation: The correct answer to the question is: HCIO4

Question 350: In a group, atomic radii increase due to successive increase of _________ ?

  • A Electronic shells
  • B Proton shells
  • C Neutron shells
  • D Nucleus

Explanation: The correct answer to the question is: Electronic shells