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level: Level 1

Questions and Answers List

level questions: Level 1

QuestionAnswer
Most abundant element in universe constitutes .... % of mass of the universe.HYDROGEN, 70%
TRITIUM is radioactive and emits low energy .... particles, with half life ..... yearsBETA, 12.33
The predominant isotope of hydrogen is....PROTIUM
Hydrogen is .... most abundant on the surface of the globe.THIRD
Methods for laboratory prep. of Dihydrogen (2)1) Rxn of zinc with dil. HCl 2) Rxn Zn with aq. alkali
Water gas consists of ... and ...CO and H2
Water gas used in synthesis of ....METHANOL and hydrocarbons
ISOTOPES have same chemical properties but differ RATES of reaction due to ...different enthalpy of bond dissociation
physical prop of H isotopes differ due tolarge mass differences
Producing .... from coal is called Coal gasificatonSyn gas
WATER GAS SHIFT REACTION catalyst?IRON (3) CHROMATE
IN water gas shift rexn CO2 is removed by scrubbing with .... solnSODIUM ARSENITE
DIHYDROGEN ISCOLORLESS
...-... BOND ENTHALPY is the highest for a single bond bn two atoms of any element?H-H
Atomic H is produced at a high temp. in an ...arc or under ...radiationselectric/UV
Hydrogenation of vegetable oils using ... as catalyst gives edible fat oils like...&...NICKEL, MARGARINE/VANASPATI GHEE
... of OLEFINS yields aldehydes which further undergo ... to give ALCHOHOLSHYDROFORMYLATION, REDUCTION
In METALLURGICAL PROCESSES, dihydrogen is used to ...REDUCE HEAVY METAL OXIDES TO METALS
...HYDROGEN & ...HYDROGEN TORCHES find use in ...&...Atomic & oxy- CUTTING / WELDING
HYDROGEN combines with almost all elements except ... to form BINARY compounds called ...noble gases, hydrides
Three categories of HydridesIONIC/ COVALENT/ METALLIC
SALINE/ SALTLIKE HALIDEIONIC HALIDE
MOLECULAR HYDRIDECOVALENT HYDRIDE
NON STOICHIOMETRIC HALIDESMETALLIC HALIDES
CO(g) + 2H2(g) --->CH3OH(l)
hydrides_ LAW of constant composition doesn't hold goodNON STOICHIOMETRIC HYDRITES
MOLECULAR HYDRITES types(3)1)E- DEFICIENT 2) E- PRECISE 3) E- RICH
COVALENT HYDRITES (volatile/not)VOLATILE
POLYMERIC metal hydritesBeH2 / MgH2
STOICHIOMETRIC HYDRITES (ionic/covalent/metallic)IONIC and COVALENT
... is unreactive with O2 and Cl2 at moderate temperatureslithium hydride
All elements of group... will form E- rich hydrides15-17
INERSTITIAL HYDRIDESMETALLIC HYDRIDES
UNUSUAL PROPERTIES OF WATER IN THE CONDENSED PHASEEXTENSIVE HYDROGEN BONDING
Ni/Pd/Ce/ AcEXCEPT hydrides of .../.../.../... other METALLIC hydrites have lattice different from parent metals
All hydrides of group ... are E- deficient13
hydrogen STORAGE (metals used)Pd/Pt CAN ACCOMODATE LARGE NO OF HYDROGEN
Property of H used in CATALYTIC reduction/hydrogenationprop: ABSORPTION OF H ON TRANSITION METALS
WHY water has high freezing pt, boiling pt, heat of fusion incomparision to H2S & H2SeHYDROGEN BONDING
ELECTRON PRECISE HYDRITES_groupgp 14 eg CH4
WHICH hydrite is used in synthesis of other hydridesLITHIUM
WHY even COVALENT COMPOUNDS like Alchohol and Carbohydrates dissolve in water?due to HYDROGEN BONDING with POLAR covalent MOLECULES
WHAT ensures survival of aquatic animals IN WINTERS when ICE forms on the surface?THERMAL INSULATION
CAGED STRUCTURE WITH LARGE HOLESICE
AT atomspheric pressure, ice crystallizes in the ...form, but at very low temperatures, it condenses to ... formHEXAGONAL CUBIC
H2O2 color in pure stateCOLORLESS/ VERY PALE BLUE
H2O2 STATE when pureliquid
H2O2 SHAPENON PLANAR book shape
Moderation of climate and body temperature of living beings _ prop. of waterHIGH HEAT OF VAPORIZATION AND HIGH HEAT CAPACITY
HOH bond angle in water104.5
HO BOND LENGTH IN PEROXIDE GAS95 PM
OO BOND LENGTH IN PEROXIDE GAS147.5 PM
HO BOND LENGTH IN PEROXIDE SOLID98.8 PM
OO BOND LENGTH IN PEROXIDE SOLID145.8 PM
DIHEDRAL ANGLE (bn HO -OO) in H2O2 GAS111.5
DIHEDRAL ANGLE (bn HO -OO) in H2O2 SOLID90.2
H20 --- OH BOND LENGTH95.7 PM
in H202, OO BOND LENGTH IS (SAME/DIFF) IN SOLID/ GASDIFFERENT
H2O2 acts as an (OXIDIZING/ REDUCING) agent in alkaline mediaBOTH
H2O2 acts as an (OXIDIZING/ REDUCING) agent in acidic mediaBOTH
H2O2 decomposes slowly in... and its decom. CATALYSED by ...LIGHT METAL/ traces of ALKALI
H202 STORED IN ...WAX LINED GLASS VESSELS or PLASTIC VESSELS IN DARK
... is added as STABILIZER to H202UREA
... can induce EXPLOSIVE DECOMPOSITION OF H2O2DUST
H202HYDROGEN PEROXIDE
PERHYDROLANTISEPTIC
H202 uses in DAILY LIFEHAIR BLEACH DISINFECTANT ANTISEPTIC
H202 used to manufacture ...& ... used in DETERGENTSSODIUM PERBORATE PER CARBONATE
H202 IS EMPLOYEED IN INDUSTRIES AS ... FOR TEXTILES, LEATHER,OILS, PAPER, FATS, etcBLEACHING AGENT
D20 is used as ... in NUCLEAR reactorsMODERATOR
COMMERCIAL production OF DI HYDROGEN (4 WAYS)1) ELECROLYSIS of acidified water w PLATINUM electrodes 2) ELECTROLYSIS of aqueous barium hydroxide solution in NICKEL electrodes 3) as a BY PRODUCT in manufacture of sodium hydroxide by electrolysis of BRINE 4) BY REACTION of STEAM with COKE or HYDROCARBONS
HIGHEST QUALITY di hydrogen is obtained byELECTROLYSING WARM AQUOUS BARIIUIM HYDROXIDE
greater ENTHALPY of FORMATION (H2O/D2O)H2O (-285) wheras D2O (-294)