A gas absorbs a photon of 355 nm and emits at two wavelengths. If one of the emissions is at 680 nm the other is at :
1. 518 nm
2.1035 nm
3.325 nm
4.743 nm
Posted Date:-2021-06-30 13:21:48
A pure substance can only be
1.Compound
2.an element
3.an element or a compound
4. a heterogeneous mixture
Posted Date:-2021-06-30 13:21:48
A radioactive substance has a half life of four months three-fourth of the substance would decay in
1.3 months
2.4 months
3.8 months
4.12 months
Posted Date:-2021-06-30 13:21:48
An atom has 7 electrons in its M - shell and contains 18 neutrons in its nucleus. What is its mass number
1.25
2.27
3.35
4.43
Posted Date:-2021-06-30 13:21:48
An element which is preserved under water is
1.sodium
2.sulphur
3. red phosphorus
4.white phosphorus
Posted Date:-2021-06-30 13:21:48
Electromagnetic radiation with maximum wavelength is
1.ultraviolet
2.radio waves
3.x-rays
4.infrared
Posted Date:-2021-06-30 13:21:48
Ethanol is converted into ethoxy ethane
1.by heating excess of ethanol with conc. H2SO4 at 140 C
2.by treating with conc. H2SO4 at room temperature
3. by treating with conc. H2SO4 at 273 K
4.by heating Ethanol with excess of conc. H2SO4 at 443 K
Posted Date:-2021-06-30 13:21:48
Ethylene glycol is used as an antifreeze in a cold climate. Mass of ethylene glycol which should be added to 4 kg of water to prevent it from freezing at –6 C will be: (Kf for
1.204.60 g
2.304.30 g
3.804.32 g
4.400.00 g
Posted Date:-2021-06-30 13:21:48
he credit for the discovery of transuranic element goes to
1.Hahn
2.Rutherford
3.Seaborg
4.Curie
Posted Date:-2021-06-30 13:21:48
Heated saw dust catches fire when a drop of concentrated nitric acid is added to it. This is due to
1.dehydration
2.oxidation
3.reduction
4.dehydrogenation
Posted Date:-2021-06-30 13:21:48
How many moles are there in 140g of Si (atomic mass of silicon is 28)
1.5
2.10
3.28
4.140
Posted Date:-2021-06-30 13:21:48
In a face centred cubic lattice atom A occupies the corner positions and atom B occupies the face centre positions. If one atom of B is missing from one of the face centred points the formula of the compound is 1) A2B5 2) A3B2 3) A2B3 4) A3B4
1.Option 1
2.Option 2
3.Option 3
4.Option 4
Posted Date:-2021-06-30 13:21:48
In known elements the maximum number is of
1.Metals
2.Non Metals
3.Metalloids
4. None of these
Posted Date:-2021-06-30 13:21:48
In nuclear reactorChain reaction is controlled by introducing
1.cadmium rod
2.iron rod
3.platinum rod
4. graphite rod
Posted Date:-2021-06-30 13:21:48
Li3PO4 compound name?
1.Lithium perchlorate
2.Lithium phyrite
3.Lithium phosphate
4.None
Posted Date:-2021-06-30 13:21:48
Most commonly used bleaching agent is
1.Chlorine
2.Alcohol
3.Carbon dioxide
4. Sodium Chloride
Posted Date:-2021-06-30 13:21:48
Natural Rubber is a Polymer of
1.butadiene
2.2methyl-13butadiene
3.ethylene
4.isoprene
Posted Date:-2021-06-30 13:21:48
Orlon is a polymer of
1.Dacron
2.Acrylonitrile
3.Polyamide Nylon
4.None of the above
Posted Date:-2021-06-30 13:21:48
Positive ions are formed from neutral atoms by loss of
1.neutrons
2.protons
3.nuclear charge
4.electrons
Posted Date:-2021-06-30 13:21:48
The bleeding of a wound is stopped by the application of ferric chloride because_____
1.Ferric chloride seals the blood vessels
2.Blood starts flowing in the opposite direction
3.Blood reacts and a solid is formed which seals the blood vessels
4.Blood is coagulated and the blood vessels are sealed
Posted Date:-2021-06-30 13:21:48
The difference between a nuclear reactor and atomic bomb is that ___________
1. no chain reaction takes place in nuclear reactor while in the atomic bomb there is a chain reaction
2.the chain reaction in nuclear reactor is controlled
3.the chain reaction in nuclear reactor is not controlled
4.no-chain reaction takes place in atomic bomb while it takes place in nuclear reactor
Posted Date:-2021-06-30 13:21:48
The freezing point of water at 760mm pressure is
1.0 K
2.273 K
3.273 C
4. -273 C
Posted Date:-2021-06-30 13:21:48
The fundamental particles present in equal numbers in neutral atoms are
1.protons and electrons
2.neutrons and electrons
3.protons and neutrons
4.protons and positrons
Posted Date:-2021-06-30 13:21:48
The isotopes of chlorine with mass number 35 and 37 exist in the ratio of
1. 1:2
2.2:03
3.3:01
4.3:04
Posted Date:-2021-06-30 13:21:48
The law of constant proportions was enunciated by
1.Dalton
2.Berthelot
3.Avogadro
4.Proust
Posted Date:-2021-06-30 13:21:48
The metal which reacts most violently with with cold water is
1.calcium
2.sodium
3.magnesium
4.potassium
Posted Date:-2021-06-30 13:21:48
The Most Abundant Rare Gas in the Atmosphere is
1.Xe
2.He
3.Ne
4.Ar
Posted Date:-2021-06-30 13:21:48
The nitrogen atom has 7 protons and 7 electronsThe nitride ion will have
1.10 protons and 7 electrons
2. 7 protons and 10 electrons
3.4 protons and 7 electrons
4.4 protons and 10 electrons
Posted Date:-2021-06-30 13:21:48
The particle with 13 protons and 10 electrons is
1.Al -atom
2. Al3+ ion
3.nitrogen isotope
4.None of these
Posted Date:-2021-06-30 13:21:48
The presence or absence of hydroxy group on which carbon atom of sugar differentiates RNA and DNA ?
1.4th
2.2nd
3.3rd
4.1st
Posted Date:-2021-06-30 13:21:48
What are long chains of Carbon Molecules called
1.Ribosomes
2.Hydrocarbons
3.Polymers
4.None
Posted Date:-2021-06-30 13:21:48
What is the conjugate base of H2O?
1.NH3+
2.OH
3.H2O
4.All the above
Posted Date:-2021-06-30 13:21:48
What is the IUPAC name of [Co(NH3)4Cl2]?
1.Tetra-ammine dichloro cobalt (III) chloride
2.Tetra-ammine trichloro cobalt (III)
3. Tri-ammine dichloro cobalt (III) chloride
4.Tetra-ammine dichloro cobalt
Posted Date:-2021-06-30 13:21:48
What is the simplest form of matter?
1.Element
2.Molecule
3.Atom
4.Compound
Posted Date:-2021-06-30 13:21:48
Which acid is produced when milk gets sour?
1.Lactic acid
2.Acetic acid
3.Tartaric acid
4.Butyric acid
Posted Date:-2021-06-30 13:21:48
Which combination of atoms can form a polar covalent bond?
1. H and Br
2.H and H
3.Na and Br
4.N and N
Posted Date:-2021-06-30 13:21:48
Which is the gas used for making vegetables and vanaspathi from vegetable oils?
1.Hydrogen
2.Nitrogen
3.Argon
4.Helium
Posted Date:-2021-06-30 13:21:48
Which Noble Gas has the highest First Ionization Energy?
1.Neon
2.Helium
3.Argon
4.Xenon
Posted Date:-2021-06-30 13:21:48
Which of the following carbon compounds is used as a fire- extinguisher?
1.Carbon disulphide
2.Chloroform
3.Carbon tetrachloride
4.Methyl ene chloride
Posted Date:-2021-06-30 13:21:48
Which of the following is the strongest acid?
1.ClCH2COOH
2.BrCH2COOH
3.FCH2COOH
4.ICH2COOH
Posted Date:-2021-06-30 13:21:48
Which of these molecules are polar? Check all that apply.
1.SO2
2.CH2Cl2
3.PCl3
4.All the above
Posted Date:-2021-06-30 13:21:48
Which one among the following is the heaviest
1.1 mole of water molecules
2.1 mole of ammonia molecules
3.1 mole of sodium atoms
4. 1 mole of hydrogen molecules
Posted Date:-2021-06-30 13:21:48
Which one is not metal
1.sulpher
2.sugar
3.nitogen
4.all of these
Posted Date:-2021-06-30 13:21:48
Which one is the pure element
1.glass
2.cement
3.sodium
4.None of these
Posted Date:-2021-06-30 13:21:48
Which one of the following can be used to confirm wether drinking water contains a gamma emitting isotope or not
1.Microscope
2.Scintillation counter
3.Lead plate
4.pectrophotometer
Posted Date:-2021-06-30 13:21:48
Which one of the following elements is the poorest conductor of heat
1.sodium
2.lead
3.zinc
4.mercury
Posted Date:-2021-06-30 13:21:48
Which one of the following is a natural colloid ?
1.Cane sugar solution
2.Blood
3.Sodium chloride solution
4.Urea solution
Posted Date:-2021-06-30 13:21:48
Which one of the following is used to induce artificial rain ?
1.Potassium Nitrate
2.Ammonium chloride
3.Calcium carbonate
4. Silver lodide
Posted Date:-2021-06-30 13:21:48
Which solution has the highest pH?
1.50.0 mL 0.0500 M calcium hydroxide Ca(OH)2 (aq)
2.50.0 mL 0.0500 M sodium hydroxide NaOH (aq)
3.50.0 mL 0.0500 M nitric acid HNO3 (aq)
4.50.0 mL 0.0500 M nitrous acid HNO2 (aq)
Posted Date:-2021-06-30 13:21:48
Who is the father of modern chemistry?
1.Priestley
2.Lavoisier
3.Dalton
4.Mendeleeff
Posted Date:-2021-06-30 13:21:48