Chemistry Sample Question for Entrance test

Sample Questions for Entrance testQuestion: 1Of the following which is paramagnetic and has three electron bond in its structureChoiceN2O NO  N2O3  N2O5Correct Answer : bQuestion: 2Boric acid is polymeric due toChoicea) Its acidic nature b) The presence of hydrogen bonds c) Its monobasic nature d) Its geometryCorrect Answer : bQuestion: 3Which oxide does not act as a reducing agentChoicea) NO b) NO2 c) N2O d) N2O5Correct Answer : dHints :In N2O5 onidation state of N is 5 and N cannot increase its orodation state beyond 5.Question: 4Which of the nitrates on strong heating leaves the metal as the residue ?Choicea) AgNO3 b) PbNO32 c) CuNO32 d) AlNO33Correct Answer : aHints :Ag is a noble metalQuestion: 5Which one of the following is not the characteristic property of carbon?Choicea) It exhibits catenation b) It forms compounds with multiple bonds c)Its melting point and boiling point are exceptionally high d) Its shows semi-metallic characterCorrect Answer : dHints :Question: 6On the addition of mineral acid to an aqueous solution of borax, the following compound is formedChoicea) Boron hydride b) Orthoboric acid c) Metabolic acid d) Pyroboric acidCorrect Answer : bHints :Na2B4O7H2SO45H2ONa2SO44H3BO3Question: 7Identify the correct statement with respect to carbon monoxide.Choicea) It combines with water to form carbonic acid b) It reacts with haemoglobin in red blood cells c) It is a powerful oxidising agent d) It is used to prepare aerated drinksCorrect Answer : bQuestion: 8Which of the following does not give a borax bead test?Choicea) Chromium b) Ferrous salt c) Sodium d) CobaltCorrect Answer : cQuestion: 9In graphite, electrons areChoicea) Localised on every third C-atom b) Present in anti-bonding orbitalc) Localised in each C-atom d) Spread out between the structureCorrect Answer : dQuestion: 10Iodine oxidises the S2O42 ion toChoicea) SO32 b) SO42 c) S4O62 d) S2Correct Answer : cQuestion: 11Ozone is notChoicea) An allotrope b) A powerful oxidising agent c) Paramagnetic d) A bent moleculeCorrect Answer : cHints :Question: 12Sulphuric acid has great affinity for water becauseChoicea) It hydroyses the acid b) It decomposes the acid c) Acid forms hydrates with water d) Acid decomposes waterCorrect Answer : cHints :Question: 13Sodium thiosulphate (Na2S2O35H2O is used in photography toChoicea) convert silver bromide to mettalic silver b) convert mettalic silver to silver salt c) Remove undecomposed AgBr as soluble complex d)Remove reduced silverCorrect Answer : cHints :Question: 14Bicaching powder reacts with a few drops of conc. HCl to giveChoicea) Chlorine b) Hypochlorous acid c) Calcium oxide d) OxygenCorrect Answer : aHints :Question: 15Which of the following hydrogen halide has the highest boiling point ?Choicea) HF b) HCl c) HBr d) HlCorrect Answer : aHints :Due to extensive H-bonding is HFQuestion: 16Fluorine is a better oxiding agent than Br2. It is due toChoicea) Small size of fluorine b) More electron repulsion in fluorine c) More electronegativity of fluorine d) Non metallic nature of flourineCorrect Answer : cQuestion: 17Helium - Oxygen mixture is used by deep sea divers in preference to nitrogen - oxygen mixture becauseChoicea) Helium is much less soluble in blood than nitrogen b) Nitrogen is much less soluble in blood than helium c) Due to high pressure deep under the sea nitrogen and oxygen react to give poisonous nitric oxide d) Nitrogen is highly soluble in waterCorrect Answer : aHints :At high pressure, He is much less soluble than N2in blood.Question: 18Among noble gases (from He to Xe) only xenon reacts with fluorine to form stable xenon fluorides because xenonChoicea) has the largest size b) has the lowest ionization enthalpy c) has the highest heat of vapourization d) is the most readily available noble gasCorrect Answer : bHints :Out of He, Ne, Ar, Kr and Xn, Xn has the lowest ionisation energy as ionisation energies decrease down a group.Question: 19If ionization potential for hydrogen atom is 13.6 eV , then ionization potential for He will beChoicea) 54.4 eV b) 6.8 eV c) 13.6 eV d) 24.5 eVCorrect Answer : aHints :I.P. of HeI.P.ofHZ2(Where Z is the atomic number of He) = 13.6eV X2254.4eVQuestion: 20The most abundant inert gas in the atmosphere isChoicea) He b) Ne c) Ar d) KrCorrect Answer : c