A small iodine crystal is added to each of the following aqueous solutions I (sodium sulphate) II (sodium thiosulphate) III (sodium tetrathionate and IV (sulphuric acid). In which solution the purple colour disappears..
1.Only in I
2.I and III
3.Only in III
4.III and IV
Acidified potassium permanganate is dropped over sodium peroxide taken in a round bottom flask at room temperature vigorous reaction takes place to produce
1.hydrogen peroxide
2.mixture of hydrogen and oxygen
3.a colourless gas hydrogen
4.a colourless gas dioxygen.
Aluminium reacts with boiling water to liberate dihydrogen gas along with the formation of
1.aluminium oxide
2.aluminium hydroxide
3.aluminium suboxide
4.aluminium superoxide.
Borax bead test is applicable to coloured salt because coloured salts.
1.are very unstable
2.are highly stable
3.form coloured metaborates
4.decolorize during the test
By starting with 0.5 mol of sodium peroxide how many moles of dioxygen gas can be obtained by dropping excess of water on it
1.0.5 mole
2.1 mole
3.0.25 mole
4.mole.
Carborundum is a very hard substance (only next to diamond in hardness) is mainly a.
1.nitride of silicon
2.zirconide of silicon
3.boride of silicon
4.carbide of silicon
Chemical name of phosgene is
1.Carbonyl chloride
2.Nitrosyl chloride
3.Phosphine
4.Phosphoryl chloride.
Conversion of atomic hydrogen into molecular hydrogen is
1.an exothermic reaction
2.endothermic reaction
3.a nuclear change
4.photochemical change.
Dipole moment of hydrogen peroxide is
1.greater than that of water
2.less than that of water
3.equal to that of water
4.unpredictable.
Hydrogen at the moment of its generation (newly born hydrogen) is generally called
1.Protium
2.Nascent hydrogen
3.Atomic hydrogen
4.Heavy hydrogen
In diborane the number of B ?.. H ?? B bonds per molecules isThree
1.Three
2.One
3.Two
4.None of these.
In general the boron trihalides act as.
1.Strong reducing agent
2.Lewis acids
3.Lewis bases
4.Dehydrating agents
In order to get ruby coloured glass which of the following compound should be added to glass mix?
1.Gold (III) chloride
2.Cobalt (II) oxide
3.Strontium chloride
4.Soft ordinary glass.
In ordinary hydrogen the approximate composition of ortho and parahydrogen is respectively
1.75% 25%
2.25% 75%
3.50% 50%
4.99% 1%.
In the laboratory preparation of hydrogen pure zinc is not used because.
1.pure zinc becomes passive due to the formation of oxide layer.
2.Pure zinc becomes passive due to the formation of sulphate layer over the metal
3.Pure zinc reacts slowly with the acid.
4.Pure zinc reacts with acid vigorously and violently.
In which of the following compound the nitrogen atom exhibits negative oxidation state
1.Sodium nitrate
2.Nitric oxide
3.Sodium azide
4.Sodium nitrite.
In which property listed below hydrogen does not resemble with alkali metals?
1.Tendency to form cation
2.Nature of oxide
3.Combination with halogens
4.Reducing character.
Mica is mainly
1.potassium aluminium silicate.
2.calcium aluminium silicate.
3.Calcium aluminium fluoride.
4.Calcium magnesium silicate.
Oleum is also called.
1.Peroxydisulphuric acid
2.Caros acid
3.Fuming sulphuric acid
4.Magic acid
Orthoboric acid on dehydration at 373 K produces mainly.
1.metaboric acid
2.boric anhydride
3.boron metal and oxygen
4.pure boric acid
Ozone oxidizes iodine in the presence of moisture to
1.Sodium nitrate
2.Nitric oxide
3.Sodium azide
4.Sodium nitrite.
Peroxide ion is isoelectronic with
1.Dihydrogen molecule
2.Dinitrogen molecule
3.Fluorine molecule
4.S atom.
Pick up the false statement about boric acid
1.Boric acid contains three OH groups per molecule.
2.Boric acid molecules are associated through H-bonds.
3.It is a tribasic acid.
4.It behaves as monobasic acid.
Saturated hydrides of silicon are called
1.Silanes
2.Silicates
3.Siloxanes
4.Silicones.
The hydrolysis of one mol of peroxdisulphuric acid produces
1.Two mole of peroxomonosulphuric acid
2.Two moles of sulphuric acid
3.One mole of sulphuric acid and one mole of peroxomonosulphuric acid and one mole of peroxomonosulphuric acid
4.One mole of sulphuric acid one mole of peroxomonosulphuric acid and one mole of hydrogen peroxide.
The main impurities present in commercial iodine are ICl IBr ICN etc. Which of the following reagent is generally used for its purification..
1.Sodium thiosulphate
2.Potassium bisulphate
3.Potassium iodide
4.Potassium iodate
The process of adsorption of hydrogen of palladium is known as
1.Syneresis
2.Occlusion
3.Diffusion
4.Erosion.
The three isotopes of hydrogen differ from one another in
1.Atomic number
2.Number of protons
3.Nuclear charge
4.Nuclear mass.
The variety of glass that is used for the manufacture of optical instruments is
1.Sodium glass
2.Flint glass
3.Ground glass
4.Quartz.
Water cannot act as
1.Oxidising agent
2.Reducing agent
3.Dehydrating agent
4.Hydrolytic agent.
When iron (III) compounds are added to glass mix which colour is imparted to it
1.Brown
2.Blue
3.Green
4.Pink.
Which compound of boron is used as a mild antiseptic for washing of eyes under the name boric lotion?.
1.Sodium borate
2.Boric acid
3.Borax
4.Sodium metaborate
Which element is kept in water?
1.Phosphorus
2.Sodium
3.Sulphur
4.Silicon.
Which elements out of the following do not produce hydrogen on treatment with caustic soda? I. (Zn) ; II. (Sn) ; III. (Mg) ; IV. (Cu) ; V. (Al)
1.I and V
2.III IV
3.IV V
4.II IV.
Which is not applicable to borax?
1.It is used as flux in soldering
2.It contains five B-O-B bonds
3.It is used in charcoal cavity test
4.It is obtained from tincal ore.
Which is wrongly matched.
1.Tritolyl phosphate-petrol additive
2.Tri-n-bulyl phosphate-wax
3.Triethyl phosphate-insecticide
4.Triphenyl phosphate-plasticizers
Which isotope of hydrogen is/are radioactive in nature?
1.Protium and deuterium
2.Tritium only
3.Tritium and deuterium
4.Only deuterium.
Which non-metallic element reacts with dioxygen at room temperature to form its corresponding oxide?
1.Carbon
2.Phosphorus
3.Sulphur
4.Nitrogen.
Which of following substance contains magnesium as well as silicon?
1.Feldspar
2.Cryolite
3.Asbestos
4.Mica.
Which of the following does not contain silicon element.
1.Quartz
2.Kaolinite
3.Asbestos
4.Fluorapatite.
Which of the following exists as tetra-atomic molecule?
1.Black phosphorus
2.Yellow phosphorus
3.Both (a) and (b)
4.Nitrogen.
Which of the following gas is lightest?
1.Dihydrogen
2.Helium
3.Dinitrogen
4.Dioxygen
Which of the following is not a use of borax?
1.It is used in charcoal cavity test of qualitative analysis
2.It is used as flux in soldering
3.It is used in preparing medicinal soap
4.It is used in preparation of pyrex glass.
Which of the following method is used to obtain pure hydrogen? Electrolysis of warm solution of barium peroxide using nickel electrodesBy the action of water on sodium hydride
1.Treatment of magnesium ribbon with pure dil.
2.Sulphuric acid
3.Electrolysis of warm solution of barium peroxide using nickel electrodesBy the action of water on sodium hydride
4.All the above mentioned methods
Which of the following statement s correct?.
1.Copper (I) metaborate is colourless
2.Copper (II) metaborate is colourless
3.Copper (II) metaborate is light green
4.Copper (I) metaborate is dark green
Which of the following type of glass is generally used in the making of cut-glass objects?
1.Crookes glass
2.Lead potash glass
3.Borosil glass
4.Soft ordinary glass.
Which out of potassium ion fluoride ion and ammonia molecule can form co-ordinate bond with boron trifluoride?
1.Only ammonia
2.Ammonia and fluoride ion
3.All the three
4.Only fluoride ion
Which pair contains species which can react with each other to produce dihydrogen gas?
1.Sodium amalgam and water
2.Hydrolith and water
3.Copper and water
4.Both (a) and (b).
Which pair of species exist as monoatomic molecules?
1.Helium and argon
2.Argon and chlorine
3.Hydrogen and helium
4.Ozone and nitrogen.
Which type of elements form ionic hydrides?
1.Transition elements
2.Metalloids
3.Elements with high electronegativity
4.Elements with high electropositivity.