FSC 2nd year chemistry 2nd chapter MCQs-S-Block elements Mcqs

Chapter 2: S-block elements

In this article, the author has explained the most important chemistry MCQs from the second chapter( S-block elements ) of FSC 2nd year chemistry. All the correct answers have been bold.

1: All of these can react with ice even at -100oC except

  1. Ca
  2. K
  3. Rb
  4. Cs

2: The pair of elements that have similar chemical properties is

  1. Beryllium
  2. Carbon and nitrogen
  3. Lithium and Magnesium
  4. Aluminum and Magnesium

3: As the alkaline earth metals (except Be) tend to lose their valence electrons readily, they act as

  1. Bases
  2. Strong reducing agents
  3. Weak oxidizing agents
  4. Weak reducing agents

Related: FSC 2nd year chemistry 1st chapter MCQs-Periodic classification of elements and periodicity Mcqs

4: KO2 is an example of

  1. Normal oxide
  2. Sub oxide
  3. Super oxide
  4. Peroxide

5: Elements of group 14

  1. From M4 and M4+ ions
  2. Exhibit oxidation state of +4
  3. Form M4+ ions
  4. Exhibit oxidation state of +4 and +2

6: All of the followings always act as bases except

  1. MgO
  2. BeO
  3. Na2O
  4. BaO

7: Noble gases are a group of elements which exhibit very

  1. High chemical activity
  2. High electronegativity
  3. Less diamagnetic property
  4. Low chemical activity

8: Which of the following is arranged in order of increasing thermal stability?

  1. BaCO3 < SrCO3 < CaCO3 < MgCO3
  2. MgCO3 < CaCO3 < SrCO3 < BaCO3 
  3. CaCO3 < MgCO3 < BaCO3 < SrCO3 
  4. MgCO3 < CaCO3 < SrCO3 < BaCO3 
  5. MgCO3 < SrCO3 <  CaCo3 < BaCO3

9: Which one of the following is correct about stability of the given ions?

  1. Sn4+ > Sn2+
  2. Pb2+ > Pb4+
  3. Pb4+ > Pb2+
  4. Si2+ >   Si4+

10: N forms NCl3 whereas P can farm bath PCl3 and PCl5 why?

  1. N atoms are larger than P atoms in size
  2. P is more reactive towards Cl than N
  3. P has low lying 3d orbitals, which can be used for banding but N does not 3d orbitals in its valence shell
  4. None of these

11: Which one of the following statements regarding helium is correct?

  1. It is used in gas-cooled nuclear reactors
  2. It is used to produce and sustain powerful super conducting magnets
  3. It is used as a cryogenic agent for carrying out experiments at low temperatures
  4. All are correct

12: In case of the oxygen family (group 16)

  1. The tendency for catenation decreases markedly as we go down the group
  2. Maximum coordination of oxygen is four due to lack of d orbital, but that of other elements is six due to presence of d orbitals
  3. The tendency to form multiple bands with C, N and O decreases as going down the group from s to Te
  4. All are correct

13: Which of the following is arranged in order of increasing melting point?

  1. Be < Ca < Sr < Mg
  2. Sr < Mg < Be < Ca
  3. Ca < Be < Mg < Sr
  4. Mg < Sr < Ca < Be

14: Alkali metals are characterized by

  1. Good conductor of heat and electricity
  2. High oxidation potentials
  3. High melting point
  4. Solubility in liquid ammonia
  5. 1,2
  6. 1,2,4
  7. 2,3,4
  8. All of these

15: The solubilities of carbonates decrease down the magnesium group due to the decrease in

  1. Hydration energies of cations
  2. Lattice energies of solids
  3. Inter ionic interaction
  4. Entropy of solution formation

16: Following statements regarding the periodic table trends of chemical reactivity of the alkali metals and the halogens are given. Which one of these statements gives the correct picture?

  1. The reactivity decrease in the alkali metals but increases in the halogens with increase in atomic number down the group
  2. In both the alkali metals and the halogens the chemical reactivity decreases with increase in atomic number down the group
  3. Chemical reactivity increases with increase in atomic number down the group in both the alkali metals and halogens
  4. In alkali metals the reactivity increases but in the halogens it decreases with increase in atomic number down the group

17: Based on lattice energy and other considerations which one of the following alkali metal chlorides is expected to have the highest melting point?

  1. LiCl
  2. KCl
  3. NaCl
  4. RbCl

18: the graph represents the variation of a property of the group II elements

What is this property?

  1. Ionic radius
  2. Neutron / proton ratio
  3. Ionization energy
  4. Rate of reaction with water

19: The products of decomposition of Mg(NO2)2 are

  1. MgO and NO2
  2. MgO, NO2 and O2
  3. Mg and NO2
  4. Mg(NO2)2

20: Which salts of alkali and alkaline earth metals do not decompose on heating?

  1. Halides
  2. Bicarbonates
  3. Nitrates
  4. None of these

21: A solution of Na in liquid NH3, serves as a good reducing agent due to the reaction;

  1. 2Na + 2NH3 —> 2NaNH2 + H2
  2. 2Na + 2H2O —> 2NaOH + H2
  3. NaNH2 + N2O —> NaN3 + H2O
  4. None of these

22: A white solid (sodium salt) on heating liberates a gas and leaves an alkaline residue. The gas turns lime water milky. The solid is

  1. Na2CO2
  2. NaHCO2
  3. NaHSO4
  4. NaNH4HPO4

23: Magnesium is present in

  1. Ascorbic acid
  2. Chlorophyll
  3. Vitamin B12
  4. Hemoglobin

24: Pick out the incorrect statements about noble gases

  1. He cannot be used in preference to nitrogen to dilute the oxygen in the gas cylinders used by divers
  2. Helium is used in weather balloons and airships
  3. Helium is used in cryoscopy to obtain the very low temperatures required for superconductivity and lasers
  4. Ar is used in metallurgical process

  5. 1 and 3
  6. 2 and 3
  7. 1 and 4
  8. 1 only

25: The calcium salt used as a fertilizer is

  1. CaC2
  2. CaCO2
  3. CaCN2
  4. CaSO4

26: The oxide that can never act as a reducing agent is

  1. SO2
  2. CO
  3. CO2
  4. NO2

27: The purest form of silica is

  1. Quartz
  2. Sand
  3. Flint
  4. Kieseiguhr

28: Chlorine acts as a bleaching agent in the presence of

  1. Dry ice
  2. Moisture
  3. Sunlight
  4. Pure oxygen

29: An element of group VIIA which does not show oxidation state equal to the group number is

  1. F
  2. Cl
  3. Br
  4. I

30: Which of the following statement is true for the halogen hydrides, HF, HCl, HBr, HI?

  1. All form intermolecular H-bonds with water in aqueous solution
  2. Bond length is greatest in HF
  3. HF cannot be oxidized to F2 by any of the other halogens
  4. An aqueous solution of HF is the strongest acid

31: The strongest reducing agent amongst the followings is

  1. HF
  2. HCl
  3. HBr
  4. HI

32: In silicon dioxide

  1. There are double bonds between silicon and oxygen atoms
  2. Silicon is bonded to two silicon atoms
  3. Each silicon atom is surrounded by two oxygen atoms and each oxygen atom is bonded to two silicon atoms
  4. Each silicon atom is surrounded by four oxygen atoms and each oxygen atom is bounded to two silicon atoms

33: In the use of chlorine as bleaching agent, the substance that is mainly responsible is

  1. HOCl
  2. CL2
  3. HCl
  4. None of these

34: Excess Cl2, during bleaching is removed by reaction with antichlor which is

  1. Na2S
  2. Na2SO3
  3. Na2SO4
  4. Na2S2O3

35: When chlorine water is exposed to sunlight, O2 is liberated: Hence

  1. Hydrogen has little affinity to O2
  2. Hydrogen has no affinity to O2
  3. Hydrogen has more affinity to chlorine
  4. It is a reducing agent

36: The halide which fails to give a precipitate with AgNO3 is

  1. F
  2. Cl
  3. Br
  4. I

37: If CO2 is passed in excess through lime water, the milkiness first formed disappears due to

  1. The solution getting heated by exothermic reaction
  2. Formation of water soluble calcium bicarbonate
  3. Reversal of the original reaction
  4. Formation of volatile calcium derivative

38: Silica is soluble in

  1. HF
  2. HNO3
  3. H2SO4
  4. HCl

39: One can obtain a silica garden if

  1. Silicon salts are grown in garden
  2. Crystals of colored cations are added to a strong solution of sodium silicate
  3. Silicon tetrafluoride is hydrolyzed
  4. Sodium silicate solution is heated with a base

40: Which of the following is most vaporizing?

  1. HI
  2. HCl
  3. HBr
  4. HF

41: Which of the following statements is false?

  1. He2 does not exist
  2. Radon is obtained from the decay of radium
  3. The most abundant rare gas found in the atmosphere is helium
  4. Xenon is the most reactive among the rare gases

42: Identify the incorrect statement among the following:

  1. Cl2 reacts with excess of NH3 to give N2 and HCl
  2. Silicon reacts with NaOH(aq) in the presence of air to give Na2SiO3 and H2O
  3. Br2 reacts with hot and strong NaOH solution to give NaBr, NaBrO4 and H2O
  4. Ozone reacts with SO2 to give SO3

43: Which of the following oxides is amphoteric in character?

  1. CO2
  2. SiO2
  3. SnO2
  4. CaO

44: Bleaching powder loses its available chlorine on standing because

  1. It changes into calcium hypochlorite and calcium carbonate
  2. It changes into calcium bicarbonate and chlorine
  3. It changes into calcium chlorate and calcium chloride
  4. It changes into calcium chlorate and calcium carbonate

45: What are the products formed when Li2CO3 undergoes decomposition?

  1. LiO2 + CO
  2. Li2O + CO
  3. Li2O + CO
  4. Li2O + CO2

46: Sodium sulfate is soluble in water but barium sulfate is sparingly soluble because

  1. The lattice energy of barium sulfate is more than its hydration energy
  2. The hydration energy of sodium sulfate is more than its lattice energy
  3. The lattice energy has no role to play in solubility
  4. The hydration energy of sodium sulfate is less than its lattice energy

47: In the manufacture of metallic sodium by the fused salt electrolysis (Down’s Process) a small amount of calcium chloride is added to

  1. Improve the electrical conduction
  2. Bring down the melt temperature
  3. Increase the temperature of electrolysis
  4. Stabilizes the metallic sodium

48: Plaster of Paris has the formula

  1. CaSO4. 2H2O
  2. (CaSO4)2 . H2O
  3. CaSO4.H2O
  4. (MgSO4)2.H2O