Multiple Choice QuestionsIn photoelectric effect, if the energy required to overcome the attractive forces on the electron, (work functions) of Li, Na and Rb are 2.41 eV, 2.30 eV and 2.09 eV respectively, the work function of 'K could approximately be in eV.
2.52
2.20
2.35
2.01
Na2S2O3 reacts with moist Cl2 to form Na2SO4, HCl and X. Which one of the following is X?
H2S
SO2
SO3
S
Heating chloroform with aqueous sodium hydroxide solution forms-
sodium acetate
sodium oxalate
sodium formate
chloral
Ni anode is used in the electrolytic extraction of
Al
Mg
Na by Down's process
Na by Castner's process
Which of the following is not correct?
LiOH is a weaker base than NaOH.
Salts of Be undergo hydrolysis
Ca(HCO3)2 is soluble in water.
Hydrolysis of beryllium carbide gives acetylene.
Assertion (A) : Alkali metals are soft and have low melting and boiling points.
Reason (R) : This is because interatomic bonds are weak.
Both (A) and (R) are not true.
(A) is true but (R) is not the correct explanation of (A).
(A) is true but (R) is false.
Both (A) and (R) are true and (R) is the correct explanation of (A).
Consider the following statements-
I. Cs+ ion is more highly hydrated than other alkali metal ions.
II. Among the alkali metals, only lithium forms a stable, nitride by direct combination with nitrogen.
III. Among the alkali metals Li, Na, K, Rb the metal, Rb has the highest melting point.
IV. Among the alkali metals Li, Na, K, Rb only Li forms peroxide when heated with oxygen.
Select the correct statement is
I
II
III
IV
Which one of the following statements is not correct?
The hydration enthalpies of alkali metal ions decrease down the group.
LIthium halides are some what covalent in nature
Alkali metals react with water liberating oxygen gas
KO2 is paramagnetic.
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