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Temporary hardness is caused due to the presence of :
Bicarbonates of Ca and Mg are responsible for temporary hardness.
Which one is correct for perhydrol?
These are characteristics of perhydrol.
Which does not react with cold water?
SiC is a giant covalent compound
H2O2 is prepared in the laboratory when:
BaO2 + CO2 + H2O → H2O2 + BaCO3
Oxygen can be obtained by heating
H2O is dipolar whereas BeF2 is not. It is beacuse:
BeF2 is linear (sp-hybridization), H2O is angular (sp3-hybridization)
The active constituent of bleaching powder is :
It is a fact
A solid compound ‘X’ on heating gives CO2 gas and a residue. The residue mixed with water forms ‘Y’ on passing an excess of CO2 through ‘Y’ in water, a clear solution ‘Z’ is obtained. On boiling ‘Z’ compound ‘X’ is reformed. The compound ‘X’ is:
Beryllium shows diagonal relationship with aluminium. Which of the following similaeity is incorrect?
Both Be(OH)2 and AI(OH)3 are amphoteric.
A metal M readily forms sulphate MSO4 which is water insoluble. It forms oxide MO which becomes inert on heating. It forms insoluble hydroxide which is soluble in NaOH. The metal M is:
BeSO4 and MgSO4 are soluble in water. Only BeO is amphoteric and thus reacts with NaOH
An inorganic compound liberates O2 when heated, turns an acid solution of KI brown and reduces acidified KMnO4. The substance is:
These are the oxidising and reducing properties of H2O2
Which statement about zeolite is false?
First three choices are characteristics of zeolites.
When zeolites, (hydrated sodium aluminium silicate) is treated with hard water, the sodium ions are exchange with :
Na2Z + Ca2+ → CaZ + 2Na+
The amount of H2O2 present in 1 L of 1.5 N H2O2 solution is:
g-eq = V (in L)*N = 1.5
w = g eq * Meq
= 1.5 * 17 = 25.5g
Which one of the following statements about water is FALSE?
There is extensive intermolecular hydrogen bonding in the condensed phase. Water is amphoteric in nature. Ice formed from D2O sinks in normal water. In photosynthesis CO2 oxidises water in presence of chlorophyll to give O2
The principal products obtained on heating iodine with concentrated caustic soda solution are:
A colourless salt gives violet colour to Bunsen flame and also turns moistured litmus paper blue. It is:
Violet colour to flame is characteristic of potassium. Also aqueous solution of K2CO3 is alkaline.
NaOH is prepared by the electrolysis of :
At anode :
2CI- → CI2 + 2e
At cathode :
2H+ + 2e → H2
Which has lowest thermal stability?
Li2CO3 decomposes on heating
li2CO3 → Li2O + CO2
What would you observe if excess of dilute NaOH solution is added and shaken with an aqueous solution of aluminum chloride?
When sodium metal is dissolved in liquid ammonia, a blue solution is formed. The blue colour is due to:
This ammoniated electron is responsible for blue colour of solution, reducing nature and good conductor nature of solution.
Anhydrous mixture of KF and HF contains which type of ions?
Due to H-bonding
Sodium thiosulphate is formed when:
Na2S + I2 + Na2SO3 → Na2S2O3 + 2NAl
Which statement is false for alkali metals?
Na gives crimson yellow colour.
Which of the following statement is correct for CsBr3?
CsBr3 → Cs++ Br-3
The raw materials in Solvay process are:
Solvay process is based on electrolysis of brine (NaCI) solution.
An aqueous solution of salt of sodium (NaX) on boiling with MgCI2 gives white precipitate, hence anion X is:
2NaHCO3 + MgCl2 → MgCO3 + 2Nacl + H2O
When magnesium is burnt in air, compounds of magnesium formed are magnesium oxide and:
Disodium hydrogen phosphate in presence of NH4CI and NH4OH gives a white ppt. with a solution of Mg2+ ion. The precipitate is:
It is a method to precipitate Mg2+ ion VI group, of qualitative analysis.
If CO2 is passed in excess into lime water, the milkiness first formed disapperars due to:
A chloride dissolves appreciably in cold water. When placed on a platinum wire in Bunsen flame, no distinctive colour is noticed. Which one is cation?
PbCI2 is insoluble in cold water. Mg2+ and Pb2+ do not show flame colour
Which alkaline earth metal nitride is volatile?
Except Be3N2, rest all are non-volatile nitrides.
The correct order of hydration energy of alkaline earth metal ion is:
maller is ion, more is hydration energy
Beryllium hydride is obtained by:
Hydrides of alkaline earth metal (except Be) are obtained by heating them in hydrogen. BeH2 is obtained by:
Which reaction shows oxidizing nature of H2O2?
The reaction H2S + H2O2 → S + 2H2O manifests:
S2- → S0 + 2e
The volume of ‘10 vol’ of H2O2 required to liberate 500 mL O2 at NTP is:
10 vol. H2O2 means that 1 mL H2O2 gives 10 mL O2; thus, 50 mL H2O2 will give 500 mL O2.
Which hydride is an ionic hydride?
It is a property of hydrogen in which it resemble with halogen, Alkali metal hydrides are ionic in nature.
H2O2 restores the colour of old lead paintings, blackened by the action of H2S gas, by:
PbS + 4H2O2 → PbSO4 + 4H2O
Some statements about heavy water are given below:
(i) Heavy water is used as a moderator in nuclear reactors (ii) Heavy water is more associated than ordinary water (iii) Heavy water is more effective solvent than ordinary water
Which of the above statements are correct?
These are facts