NEET Chemistry Chapter Wise Mock Test – s-Block Elements
Alkali metals impart colour to Bunsen flame due to
(a) low ionisation energy
(b) low melting point
(c) their softness
(d) the presence of one electron in the outer most shell
Which of the following are arranged in correct increasing order of solubilities?
(a)CaC03 < KHCOg < NaHCO3
(b)NaHCO3< KHCOg < CaC03
(c)KHCO3 < NaHCOg < CaCO3
(d)CaCO3 < NaHCOg < KHCO3
The alkali metals form salt-like hydride by the direct synthesis at elevated temperature. The thermal stability of these hydrides decreases in which of the following orders?
(a) CsH > RbH > KH > NaH > LiH
(b) KH > NaH > LiH > CsH > RbH
(c) NaH > LiH > KH > RbH > CsH
(d) LiH > NaH > KH > RbH > CsH
Mg burns in CO to produce
(c)MgO + C
Which pair of the following chlorides do not impart colour to the flame?
(a) BeCI2 and SrCI2
(b) BeCI2and MgCI2
(c) CaCI2 and BaCI2
(d) BaCI2 and SrCI2
Shine at freshly cut sodium is
(a) due to oscillation of free electrons
(b) due to weak metallic bonding
(c) due to absorption of light in crystal lattice
(d) due to the presence of free valency at the surface
In the alkaline earth metals, the element forming predominantly covalent compound is
A metal M readily forms its sulphate MS02 which is water soluble. It forms its oxide MO which becomes inert on heating. It forms its insoluble hydroxide M(OH)2 which is soluble in NaOH. Then M is
BaS04 is insoluble in water due to its
(a) high hydration energy
(b) high lattice energy
(c) high ionisation energy
(d) high kinetic energy
The correct sequence of increasing covalent character is represented by
(a) LiCI < NaCI < BeCI2
(b) BeCI2 < NaCI < LiCI
(c)NaCI < LiCI < BeCI2
(d) BeCI2 < LiCI < NaCI
Amphoteric hydroxides react with both alkalies and acids. Which of the following group 2 metal hydroxides is soluble in sodium hydroxide?
Which is the weakest reduction agent?
Among the alkali metals, caesium is the most reactive because
(a) its incomplete shell is nearest to the nucleus
(b) it has a single electron in the valence shell
(c) it is the heaviest alkali metal
(d) the outermost electron is more loosely bound than the . outermost electron of the other alkali metals
Which of the following statements is true about Ca(OH)2?
(a) It is used in the preparation of bleaching powder
(b) It is a light blue solid
(c) It does not possess disinfectant property
(d) It is used in the manufacture of cement
When sodium is dissolved in liquid ammonia, a solution of deep blue colour is obtained. The colour of the solution is due to
(a) ammoniated electron
(b) sodium ion
(c) sodium amide
(d) ammoniated sodium ion
A solution of sodium metal in liquid NH3 is strongly reducing due to the presence of
Sodium peroxide which is a yellow solid, when exposed to air becomes white due to the formation of
(d) NaOH and Na2C03
When sodium is heated with moist air, the product obtained is
The alkali metal that reacts with nitrogen directly to form nitride is
The correct order of increasing thermal stabilities of K2C03, MgC03, CaC03 and BeC03 is
(a) BeC03 < MgC03 < K2C03 < CaC03 .
(b) BeC03 < MgC03 < CaC03 < K2C03
(c) MgC03 < BeC03 < CaC03 < K2C03
(d) K2C03 < MgC03 < CaC03 < BeC03
A solid compound X on heating gives C02 gas and a residue. The residue mixed with water forms Y. On passing an excess of C02through Y in water, a clear solution, Z. On boiling Z, compound, X is reformed. The compound X is
Sodium thiosulphate is prepared by
(a)boiling Na2S03 solution with S in alkaline medium
(b)reducing Na2S04 solution with H2S
(c)boiling Na2S03 solution with S in acidic medium
(d)neutralising H2S203 solution with NaOH
Fire extinguisher contain H2SO4 and
(d) All of these
K2C03 cannot be prepared by Solvay ammonia process because
(a) K2C03 is fairly soluble in water
(b) it has no water of crystallisations
(c) KHC03is highly soluble in water
(d) K2C03 decomposes in H20
When washing soda is heated
(a) CO is released
(b) CO+ C02 is released
(c) C02 is released
(d) water vapour is released
Microcosmic salt is
Fusion mixture is
(a) KHS04+ Na2S03
(b) K2C03 + NaHS04
(c) KHS04 + NaHS04
(d) K2C03+ Na2C03
Several blocks of magnesium are fixed to the bottom of a ship to
(a) keep away the sharks
(b) make the ship lighter
(c) prevent action of water and salt
(d) prevent puncturing by under-sea rocks
The pair whose both species are used in antiacid medicinal preparations is
(a) NaHC03 and Mg(QH)2
(b) Na2C03 and Ca(HC03)2
(c) Ca(HC03)2 and Mg(OH)2
(d) Ca(OH)2 and NaHC03
Direction (Q. Nos. 36-37) In the following questions more than one of the answers given may be correct. Select the correct answer and mark it according to the codes.
(a) 1,2 and 3 are correct
(b) 1 and 2 are correct
(c) 2 and 4 are correct
(d) 1 and 3 are correct
Identify the correct formula of halides of alkaline earth metals from the following
(a) BaCI2 -2H20
(b) BaCI2 -4H20
(c) CaCI2 -6H20
Highly pure dilute solution of sodium in liquid ammonia
(a)shows blue colour
(b) exhibits electrical conductivity
(c) produces sodium amide
(d)produces hydrogen gas
Direction (Q. Nos. 39-42) Each oj^th^sequestions contains two statements : Assertion and kedsoh. Each of these questions also has four alternative choices, only one of which is the correct answer. You have to select one of the codes (a),(b) , (c) and (d) given below.
(a) .Assertion is true, Reason is true; Reason is a correct explanation for Assertion
(b) Assertion is true, Reason is true; Reason is not a correct explanation for Assertion
(c) Assertion is true, Reason is false
(d) Assertion is false, Reason is true
Assertion Group 1 (IA) elements are known as the alkali elements.
Reason s-orbital can accommodate only two electrons.
Assertion Radium is most abundant s-block element.
Reason Except francium (Fr), all s-biock elements are non-radioactive in nature.
Assertion The first ionisation enthalpy of Be is greater than that of B.
Reason 2p-orbtial is lower in energy than 2s-orbital.
Assertion K, Rb and Cs form superoxides.
Reason The stability of the superoxides increases from K to Cs due to decrease in lattice energy.
Solubility of the alkaline earth’s metal sulphates in water decreases in the sequence
(a) Mg > Ca > Sr > Ba
(b) Ca > Sr > Ba > Mg
(c) Sr > Ca > Mg > Ba
(d) Ba > Mg > Sr > Ca
Which one of the alkali metals forms only, the normal oxide, M20 on heating in air?
Property of the alkaline earth metals that increases with their atomic number
(a) solubility of their hydroxides in water
(b) solubility of their sulphates in water
(c) ionisation energy
Which of the following alkaline earth metal sulphate
has hydration enthalpy higher than the lattice enthalpy?
In which process, fused sodium hydroxide is electrolysed for extraction of sodium?
(a) Castner’s process
(b) Cyanide process
(c) Down’s process
(d) Both (a) and (c)
Which of the following carbonates is the most stable?
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