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The ratio of mass percent of C and H of an organic compound (C_XH_YO_Z) is 6 : 1. If one molecule of the above compound (C_XH_YO_Z) contains half as much oxygen as required to burn one molecule of compound C_XH_Y completely to CO₂ and H₂O. The empirical formula of compound C_XH_YO_Z is

1) C2H4O 2) C3H4O2 3) C2H4O3 4) C3H6O3 Answer: (3) Element Relative mass Relative mole Simplest whole number ratio... View Article

The trans-alkenes are formed by the reduction of alkynes with

1) NaBH4 2) Na/liq. NH3 3) Sn - HCl 4) H2-Pd/C, BaSO4 Answer: (2) So, option (2) is correct.... View Article

Consider the following reaction and statements [Co(NH₃)₄Br₂]⁺ + Br^– [Co(NH₃)₃Br₃]+NH₃

(I) Two isomers are produced if the reactant complex ion is a cis-isomer (II) Two isomers are produced if the reactant complex ion is a... View Article

The recommended concentration of fluoride ion in drinking water is up to 1 ppm as fluoride ion is required to make teeth enamel harder by converting [3Ca₃(PO₄)₂.Ca(OH)₂] to

1) [3Ca(F)2.Ca(OH)2] 2) [3Ca3(PO4)2.CaF2] 3) [3{Ca(OH)2}.Ca(F)2] 4) [CaF2] Answer: (2) F- ions make the teeth enamel harder by converting... View Article

The predominant form of histamine present in human blood is (pK_a Histidine = 6.0)

Answer: 3 At pH (7.4) major form of histamine is protonated at primary amine.... View Article

Glucose on prolonged heating with HI gives

1) 1-Hexene 2) Hexanoic acid 3) 6-iodohexanal 4) n-Hexane Answer: (4)... View Article

Hydrogen peroxide oxidises [Fe(CN)₆]^4- to [Fe(CN)₆]^3- in acidic medium but reduces [Fe(CN)₆]^3- to [Fe(CN)₆]^4- in alkaline medium. The other products formed are, respectively.

1) (H2O+O2) and (H2O+OH-) 2) H2O and (H2O+O2) 3) H2O and (H2O+ OH-) 4) (H2O+O2) and H2O Answer: (2)... View Article

The oxidation states of Cr in [Cr(H₂O)₆]Cl₃, [Cr(C₆H₆)₂] and K₂[Cr(CN)₂(O)₂(O₂)(NH₃)] respectively are

1) +3, +2 and +4 2) +3, 0 and +6 3) +3, 0 and +4 4) +3, +4 and +6 Answer: (2) [Cr(H2O)6]Cl3 ⇒ x+0×6-1×3 = 0 x = +3 [Cr(C6H6)2]... View Article

Which of the following compounds contain(s) no covalent bond(s)? KCl, PH₃, O₂, B₂H₆, H₂SO₄

1) KCl, H2SO4 2) KCl 3) KCl, B2H6 4) KCl, B2H6, PH3 Answer: (2) KCl - Ionic bond between K+ and Cl– PH3- Covalent bond between P and H... View Article

Which type of ‘defect’ has the presence of cations in the interstitial sites?

1) Vacancy defect 2) Frenkel defect 3) Metal deficiency defect 4) Schottky defect Answer (2) In Frenkel defect, cation is dislocated from... View Article

The correct order of basicity of the following compound is :

1) (b) < (a) < (c) < (d) 2) (b) < (a) < (d) < (c) 3) (d) < (b) < (a) < (c) 4) (a) < (b) < (c) < (d)... View Article

According to molecular orbital theory, which of the following will not be a viable molecule?

1) He2+ 2) H2- 3) H22- 4) He22+ Answer: (3) Molecule having zero bond order will not be a viable molecule.... View Article

When metal ‘M’ is treated with NaOH, a white gelatinous precipitate ‘X’ is obtained, which is soluble in excess of NaOH. Compound ‘X’ when heated strongly gives an oxide which is used in chromatography as an adsorbent. The metal ‘M’ is

1) Ca 2) Al 3) Fe 4) Zn Answer: (2) Al2O3 is used in column chromatography.... View Article

Total number of lone pair of electrons in I₃ ion is

1) 6 2) 9 3) 12 4) 3 Answer: (2) Structure of I3- Number of lone pairs in I3- is 9.... View Article

How long (approximate) should water be electrolysed by passing through 100 amperes current so that the oxygen released can completely burn 27.66 g of diborane? (Atomic weight of B = 10.8 u)

1) 0.8 hours 2) 3.2 hours 3) 1.6 hours 4) 6.4 hours Answer: (2) B2H6 +3O2 -> B2O3 +3H2O 27.66 of B2H6 = 1 mole of B2H6 which requires... View Article

The compound that does not produce nitrogen gas by the thermal decomposition is

1) (NH4)2Cr2O7 2) NH4NO2 3) (NH4)2SO4 4) Ba(N3)2 Answer: (3) Among all the given compounds, only (NH4)2SO4 do not form dinitrogen on... View Article

The combustion of benzene (l) gives CO₂(g) and H₂O (l). Given that heat of combustion of benzene at constant volume is -3263.9 kJ mol ^-1 at 25⁰C ; heat of combustion (in kJ/mol) of benzene at constant pressure will be (R = 8.314 JK^-1 mol^-1)

1) -452.46 2) 3260 3) -3267.6 4) 4152.6 Answer: (3) C6H6 (l) + (15/2)O2 (g) -> 6CO2 (g) + 3H2O (l) Δng = 6-(15/2) = -3/2 ΔH = ΔU +ΔngRT... View Article

An aqueous solution contain 0.10 M H₂S and 0.20 M HCl. If the equilibrium constant for the formation of HS^– from H₂S is 1.0×10^-7 and that of S^2- from HS^– ions is 1.2×10^-13 then the concentration of S^2- ions in aqueous solution is

1) 3×10-20 2) 6×10-21 3) 5×10-19 4) 5×10-8 Answer: (1) Ka1.Ka2 = Keq [S2-] = 3×10-20... View Article

An alkali is titrated against an acid with methyl orange as indicator, which of the following is a correct combination?

Base Acid End point 1. Strong Strong Pinkish red to yellow 2. Weak Strong... View Article

Which of the following are Lewis acids?

1) AlCl3 and SiCl4 2) PH3 and SiCl4 3) BCl3 and AlCl3 4) PH3 and BCl3 Answer: (3) BCl3 - electron deficient, incomplete octet AlCl3 -... View Article