Which of the following compound is obtained on passing ethanol vapours on heated Al₂O₃?
When ethernal vapours are passed on heated , Aluminia ether compound is mainly formed. Therefore, A is the correct option.
Dow's reaction involves
On acidic hydrolysis of sodium phenoxide , gives phenol . This process of preparation of phenol from chloro benzene is known as Dow process . The Dow process is an aromatic nucleophilic substitution reaction . The reaction is carried out through active benzyne inter mediate formation
Which of the following cannot reduce Fehling solution?
CH3COOH (acetic acid) cannot reduce Fehling solution while HCOOH, HCHO and CH3CHO reduce Fehling solution due to the presence of CHO group
Electronic configuration of deuterium atom is
Deuterium is an isotope of hydrogen and atomic no. of hydrogen is 1 so the electronic configuration of deuterium is 1s1
The atomic numbers of elements X, Y, and Z are 19, 21, and 25 respectively. The number of electrons present in the M-shells of these elements follow the order.
19(X) = 1s2 2s2 2p6 3s2 3p6 4s1
so M shell means 3rd shell has 8 electrons
21(Y) = 1s2 2s2 2p6 3s2 3p6 4s2 3d1
so M shell has 9 electrons
25(Z) = 1s2 2s2 2p6 3s2 3p6 4s2 3d5
so M shell has 13 electrons hence the order is Z>Y>X
Which of the followng acts to inhibit lutenizing hormone secretion?
There are two gonadotrophic hormone: follicle stimulating hormone (FSH) and luteinizing hormone (LH), in both males and females. In males, FSH promotes spermatogenesis in the seminiferous tubules, which also release the hormone inhibin. Inhibin acts to inhibit luteinizing hormone secretion by the anterior pituitary gland
Vitamin B₁₂ contains
Electrolysis of aqueous solution of CH₃COOK gives
Two methyl free radical combine to form ethane , this electrolysis method(kolbes electrolysis) is used for preparation of even number of carbon containing alkanes.
Which one of the following is the correct set with reference to molecular formula, hybridisation of central atom and shape of the molecule
In CO2, O = C = O is the structural formula and C is sp hybridised. CO2 is linear molecule.
In H2O, Oxygen is sp3 hybridised and shape is angular.
In BeCl2, Be is sp hybridised with no lone pairs and is a linear molecule.
If a mixture containing 3 moles of hydrogen and 1 mole of nitrogen is converted completely into ammonia, the ratio of volumes of reactants and products at the same temperature and pressure would be
3H2 + N2 → 2NH3
∴ 3V 1V → 2V
Total initial volume = 3V + 1V = 4V
Final volume = 2V
Hence, ratio of initial and final volume will be 2 : 1
The facor which changes equilibrium constant of the reaction A₂(g) + B₂(g) → 2AB(g) is
Equilibrium constant depends on temperature and is independent of the presence of a catalyst. It is also independent of concentrations, pressures and volumes of reactants and products.
The first ionisation potentials of four consecutive elements, present in the second period of the periodic table are 8.3, 11.3, 14.5 and 13.6 eV respectively. Which one of the following is the first ionisation potential (in eV) of nitrogen?
As N has extra stable half-filled electronic configuration (1s2 2s2 2p3) , therefore it is difficult to remove an electron from nitrogen and ionisation potential of N is higher.
The activation energy of a chemical reaction can be determined by
Half life period of 2nd order reaction is
Which of the following endothermic process is spontaneous?
In the conversion of ice to water and water to water vapour entropy increases at both steps therefore these conversions are spontaneous.
Which of the following is an azo dye?
Orange 1 is red organic compound known as azo dyes.
Identify the correct order in which the ionic radius of the following ions increases:
I) F −
III) N3 −
The size of cation is always smaller than the corresponding atom. This is because, due to the removal of electron (or electrons) from the neutral atom, the number of electrons in the cation decreases, but its nuclear charge remains the same as that of the atom. As a result, the force of attraction by the nucleus on the electrons increases, and the size of the atom decreases. Similarly, the size of anion is always larger than the corresponding atom due to the small effective nuclear charge and large screening effect.
The synthetic product which closely resembles with the natural musk in odour is
In which of the following reaction, hydrogen is acting as an oxidising agent?
An oxidising agent itself undergoes reduction. Its oxidation number decreases. When H2 is converted to hydride ion H−, it itself is reduced and acts as oxidisng agent.
In the following reactions, hydrogen is acting as an oxidising agent.
With lithium to give lithium hydride
In the following reactions, hydrogen is acting as a reducing agent.
With iodine to give hydrogen iodine
With nitrogen to give ammonia
With sulphur to give hydrogen sulphide
Which of the following alkanes has neither secondary nor tertiary hydrogens ?
Neopentane is the only compound which has neither secondary nor tertiary hydrogen as the centre carbon's valency is satisfied by 4 other carbons (methyl groups) and not by hydrogen atoms.
The oxidation number of sulphur in Na₂S₄O₆ is
Oxidation no.of Na = 1
oxidation no. of O = -2
let oxidation no of S = x
2(1) + 4(x) + 6(-2) = 0
2 + 4x - 12 = 0
4x = 10
x = 2.5
Presence of which of the following salts increases the rate of setting of plaster of paris.
NaCl as it increase the hydration & rearrangment process of the reaction of the constituent materials.
An aqueous solution of sodium carbonate is alkaline because sodium carbonate is a salt of
Pyrolusite is /an
Pyrolusite is manganese dioxide (MnO2) and is an oxide ore of manganese. It is a black, amorphous appearing mineral, often with a granular, fibrous, or columnar structure.
Lithium and magnesium are similar in their properties due to the same
Mg and Li have similar properties due to diagonal relationship. They behave similarly due to same polarising power which depends on the ratio of ionic charge to ionic radius, in short they have same ionic potential
Which of the following isomers will have the highest boiling point ?
The compound that decolourises alkaline KMnO₄ is
Baeyer's reagent is alkaline KMnO4, it reacts with unsaturated hydrocarbon (alkene, alkyne, etc.) and decolourises its pink colour. And silver nitrate reacts with acidic hydrogen of alkyne and makes white precipitate. Among the given options, methane and ethane are alkanes, so they don't react with either solution.
Ethylene is unsaturated but doesn't have acidic hydrogen, so it react with Baeyer's reagent but does not react with silver nitrate. Alkyne reacts with both reagents.
Which of the following will not displace hydrogen
According to standard electrode, Ba,Pb and Sn have lower reduction potential than H+ so, they can reduce it to H2 but as Hg has higher reduction potential than H+ so, it can not reduce it.
The solubility of AgI in NaI solution is less than that in pure water because
The half life period of a radioactive material is 15 minutes. What percent of radioactivity of that material will remain after 45 minutes?
n = 45 / 15 = 3,
Amount left =
1 / 23 [A0] = 1 / 8 [Ao] = 12.5%
Ca2⁺ is isoelectronic with
Ca2+ contains 18 electrons and Ar also contains 18 electrons hence both are isoelectronic.
Beta-partilces is emitted in radioactivity by
In the presence of AlCl3, benzene and n - propyl bromide react in Friedel-Craft's reaction to form
Benzene reacts with n-propyl chloride in the presence of anhydrous aluminum chloride to give predominantly isopropylbenzene also known as cumene. In this reaction, n propyl group rearranges to isopropyl group.
Aniline when diazotised in cold and then treated with dimethyl aniline gives a coloured product. Its structure would be
The reaction of chloroform with alcoholic KOH and p-toluidine forms
When ammonium nitrate is gently heated, an oxide of nitrogen is formed. What is the oxidation state of nitrogen in this oxide?
When ammonium nitrate is gently heated, dinitrogen monoxide N2O is obtained.
Let x be the oxidation state of N in N2O.
The oxidation state of oxygen is −2.
The sum of the oxidation states for neutral molecule is 0.
Hence, 2x+(−2)=0 or, x=+1.
Therefore, the oxidation state of N is +1.
Bio-gas and producer gas are made up of
Producer gas is a fuel gas. It is made from coke, anthracite or other carbonaceous. It is quite toxic because it produces a large amount of carbon monoxide. Biogas is produced by an anaerobic breakdown of biomass (cattle dung) and through this process large amount of methane along with carbon dioxide produced.
Which of the following oxyacid does not exist?
The reason is inert pair effect
in the given acid the oxidation state of bismuth is +5. but in bismuth the stability of higher oxidation state is very less. so this acid can not exist.
HBiO₃ = It should be H3BiO3. Only then it will have +3 oxidation state which is a stable state for Bi.
Borazole is known as
Which is an example of thermosetting polymer?
Bakelite is an example of a thermosetting polymer.
(1) Neoprene rubber
(2) PVC is a thermoplastic
(3) Polyethene is thermoplastic polumer.
(4) Bakelite is a thermosetting polymer
On the basis of the mode of their formation the polymers can be classified
Which of the following is a redox reaction?
Benzoic acid undergoes dimerisation in benzene solution. The Vant's Hoff factor 'i' is related to the degree of dissociation 'α' of the acid as
α = i - 1 / 1 / M - 1
or α = i - 1 / 1 / 2 - 1
or i - 1 = α (1 / 2 - 1)
or i = 1 + α (-1 / 2)
= 1 - α / 2
The number of moles of KCl in 1000 ml of 3 molal solution is
Given that :
Molarity = 3M
Volume = 1000 in ml= 1L
We have to find no of moles :
Molarity = moles / volume
No of moles = molarity x volume(in L)
No. of moles=3 x 1 mol = 3 mol
Which is distilled first?
Liquids having low molecular mass will distill first
So according to this,here H2 has lowest molecular mass among all, so it will distill first
The inter ionic distance in cesium chloride crystal will be (a = edge length)
Scattering of light takes place in
Scattering of light takes place in colloidal solution. Tyndall effect refers to the process by which light is scattered by colloids or suspension making the path of light to be visible. When light seeps in through the canopy one clear see it's path.
German silver is an alloy of
German silver, name for various alloys of copper, zinc, and nickel, sometimes also containing lead and tin. They were originally named for their silver-white color, but use of the term silver is now prohibited for alloys not containing that metal.
Common oxidation state of scandium, a transition element, is/are [Ar.No.of Sc = 21]
Which of the following has the maximum number of unpaired d electrons ?
Fe2+ has the maximum number of unpaired d-electrons.
Zn(30) = [Ar]3d10,4s2
Zn2+ = [Ar]3d10: No unpaired electron
Fe(26) = [Ar]3d6,4s2
Fe2+ = [Ar]3d6: Four unpaired electrons.
Ni(28) = [Ar]3d8,4s2
Ni3+ = [Ar]3d7: Three unpaired electrons.
Cu(29) = [Ar]3d10,4s1
Cu+ = [Ar]3d10: No unpaired electrons.