On heating Li2CO3 and Na2CO3.10H2O, residue is left after heating. The weight loss is due to
Evolution of CO2 from Na2CO3.10H2O only
Evolution of CO2 from Li2CO3 only
Due to evolution of CO2 from Li2CO3 and H2O from Na2CO3.10H2O
H2O from Na2CO3.10H2O
Ionic mobility of which of the following alkali metal ions is lowest when an aqueous solution of their salts are put under an electric field?
Na
K
Rb
Li
The suspension of slaked lime in water is known as -
Limewater.
Quicklime.
Milk of lime.
Aqueous solution of slaked lime.
The incorrect statement among the following regarding Beryllium is-
It is rendered passive by nitric acid.
lt forms Be2C
It's salts rarely hydrolyze.
It's hydride is electron-deficient and polymeric.
"Metals are usually not found as nitrates in their ores'"
Out of the following two (I and II) reasons which is/are true for the above observation?
I. Metal nitrates are highly unstable.
II. Metal nitrates are highly soluble in water.
I and ll are true
I and II are false
I is false but ll is true
l is true but ll is tase
A compound that releases CO2 most easily upon heating is -
K2CO3
Na2CO3
MgCO3
CaCO3
An active ingredient in bleaching powder for bleaching action is -
Ca(OCl)2
CaO2Cl
CaCl2
CaOCl2
An alkaline earth metal sulphate that has hydration enthalpy higher than the lattice enthalpy is -
CaSO4
BeSO4
BaSO4
SrSO4
Property of the alkaline earth metals that increases with their atomic number is -
Solubility of their hydroxides in water.
Solubility of their sulphates in water.
Ionisation energy.
Electronegativity.
The thermal stability of these hydrides decreases in which of the following orders?
CsH > RbH > KH > NaH > LiH
KH > NaH > LiH > CsH > RbH
NaH > LiH > KH > RbH > CsH
LiH > NaH > KH > RbH > CsH
Which of the following compounds has a positive enthalpy of solution?
LiF
LiCl
LiBr
Lil
Which of the following metal on burning in moist air does not give the smell of ammonia?
Mg
Ca
Among the carbonates of alkali metals which one has highest thermal stability?
Cs2CO3
Rb2CO3
Incorrect statement is:
()NaHCO3 and KHCO3 have same crystal structure
() On heating LiNO3 decomposes into Li2O and NO2
() Among alkali metals, Li metal impart red colour to flame
() Li2SO4 does not form alum
The solubility of metal halides depends on their nature, lattice enthalpy and hydration enthalpy of the individual ions. Amongst fluorides of alkali metals, the lowest solubility of LiF in water is due to:
Ionic nature of lithium fluoride
High lattice enthalpy
High hydration enthalpy of lithium ion
Low ionisation enthalpy of lithium atom
The strongest factor responsible for reducing action of Li metal in an aqueous solution is :
Sublimation enthalpy .
Ionisation enthalpy.
Hydration enthalpy .
Electron-gain enthalpy.
The effect of addion of gypsum to cement is-
It reduces the setting time of cement .
The setting time of cement increases.
The colour of cement becomes light .
A shining surface is obtained.
A compound (A) is used in the preparation of washing soda to recover ammonia in Solvay's process. When CO2 is bubbled through an aqueous solution of (A), the solution turns milky. It is used in whitewashing due to its disinfectant nature. The chemical formula of A is :
CaHCO32
CaO
CaOH2
Which of the following statement about the sulphate of alkali metal is correct?
Expect Li2SO4 all sulphate of other alkali metals are soluble in hot water
All sulphate salts of alkali metals except lithium sulphate forms alum.
All sulphate salts of alkali metals except lithium sulphate do not decompose at high temperature
All of the above
When a standard solution of NaOH is left in air for a few hours :
a precipitate will form
strength of solution will decrease
the strength of solution will increase
the concentration of Na+.ion in solution will remains same
CaCl2 is preferred over NaCl for clearing ice on roads particularly in very cold countries. This is because:
CaCl2 is less soluble in H2O than NaCl.
CaCl2 is hygroscopic but NaCl is not.
Eutectic mixture of CaCl2/H2O freezes at -55°C while that of NaCl/H2O freezes at -18°C.
NaCl makes the road slippery but CaCl2 does not.
Which metal bicarbonates does not exist in solid state?
(i) LiHCO3 (ii) CaHCO32 (iii) ZnHCO32 (iv)AgHCO3
i,ii,iii,iv
i,ii,iii
i,ii,iv
ii,iii,iv
The incorrect statement among the following is-
The milk of magnesia used as an antacid is chemically MgO + MgCl2
Stability of alkali metal peroxides increases with an increase in atomic number.
Hydration energy of AgF is higher than its lattice energy.
Anhydrous MgCl2 cannot be prepared by direct heating of MgCl2 . 6H2O.
Calcium imide on hydrolysis gives gas (B) which on oxidation by bleaching powder gives gas (C). Gas (C) on reaction with magnesium give compound (D) which on hydrolysis gives again gas (B)> Identify (B), (C) and (D).
NH3, N2, Mg3N2
N2, NH3, MgNH
N2, N2O5, MgNO32
NH3 ,NO2, MgNO22
Give the correct order of initials T or F for following statements. Use T if statement is true and F if it is false.
(I) Numbers of S—S bonds in H2SnO6 are (n+1)(II) When F2 reacts with water gives HF, O2 and O3(III) LiNO3 and BaCl2 compounds are used in fire works (IV) Be and Mg are ionic and polymeric(a) FTTF (b) FTTT (c) TFTT (d) TTFF
Which of the following statements is true for all the alkali metals?
Their nitrate decomposes on heating to give the corresponding nitrites and oxygen.
Their chlorides are deliquescent and crystallize as hydrates.
They react with water to form hydroxide and hydrogen.
They readily react with halogens to form ionic halides. M+X-.
Which of the following statements is not true about the dilute solutions of alkali metals in liquid ammonia?
They are deep blue coloured solutions.
They are highly conducting in nature.
They are diamagnetic in nature.
Ammoniated cations and ammoniated anions are formed in a solution.
Which is not correctly matched?
(1) Basic strength of oxides Cs2O<Rb2O<K2O<Na2O<LiO2
(2) Stability of peroxides Na2O <K2O2<Rb2O2<Cs2O2
(3) Stability of bicarbonate LiHCO3<NaHCO3<KHCO3<RbHCO3<Cs HCO3
(4) Melting Point NaF<NaCl<NaBr<Nal
(A) 1 nd 4
(B) 1 and 3
(C) 1 and 2
(D) 2 an 3
In manufacture of sodium carbonate from Solvay (or ammonia-soda) process the raw material used is :
NaOH
Na2SO4
NaCl
NaHCO3
Which of the following reactions of potassium superoxide supply oxygen gas in the breathing equipments used in space and submarines?
(1) Reaction of superoxide with nitrogen in the exhaled air.
(2) Reaction of superoxide with moisture in the exhaled air.
(3) Reaction of superoxide with carbon dioxide in the exhaled air
(1), (2) and (3)
(2) and (3) only
(2) only
(1) and (2) only
Please disable the adBlock and continue. Thank you.