Chemistry
Some Basic Concepts of Chemistry
Previous Years Questions

## MCQ (More than One Correct Answer)

To check the principle of multiple proportions, a series of pure binary compounds $\left(\mathrm{P}_{\mathrm{m}} \mathrm{Q}_{\mathrm{n}}\right)$ were...

## Numerical

The treatment of an aqueous solution of $3.74 \mathrm{~g}$ of $\mathrm{Cu}\left(\mathrm{NO}_{3}\right)_{2}$ with excess KI results in a brown solution...
In the chemical reaction between stoichiometric quantities of KMnO4 and KI in weakly basic solution, what is the number of moles of I2 released for 4 ...
5.00 mL of 0.10 M oxalic acid solution taken in a conical flask is titrated against NaOH from a burette using phenolphthalein indicator. The volume of...
The mole fraction of urea in an aqueous urea solution containing 900 g of water is 0.05. If the density of the solution is 1.2 g cm$$-$$3, then molari...
The amount of water produced (in g) in the oxidation of 1 mole of rhombic sulphur by conc. HNO3 to a compound with the highest oxidation state of sulp...
To measure the quantity of $$MnC{l_2}$$ dissolved in an aqueous solution, it was completely converted to $$KMn{O_4}$$ using the reaction, $$MnC{l_2}... If the value of Avogadro number is 6.023$$\times$$1023 mol-1 and the value of Boltzmann constant is 1.380$$\times$$10-23 J K-1, then the number of... 29.2 % (w/w) HCl stock solution has density of 1.25 g mL -1 . The molecular weight of HCl is 36.5 g mol -1 . The volume (mL) of stock solution require... A student performs a titration with different burettes and finds titre values of 25.2 mL, 25.25 mL, and 25.0 mL. The number of significant figures in ... Silver (atomic weight = 108 g mol-1) has a density of 10.5 g.cm-3. The number of silver atoms on a surface of area 10-12 m2 can be expressed in scient... 2.68$$\times$$10-3 moles of a solution containing an ion An+ require 1.61$$\times$$10-3 moles of$$MnO_4^-$$for the oxidation of An+ to$$AO_3^-\$...

## MCQ (Single Correct Answer)

Dissolving 120 g of urea (mol. wt. 60) in 1000 g of water gave a solution of density 1.15 g/mL. The molarity of the solution is
Given that the abundances of isotopes 54Fe, 56Fe and 57Fe are 5%, 90% and 5%, respectively, the atomic mass of Fe is :...
Consider a titration of potassium dichromate solution with acidified Mohr’s salt solution using diphenylamine as indicator. The number of moles of Moh...
The pair of compounds having metals in their highest oxidation state is
Which has maximum number of atoms?
Mixture X = 0.02 mol of [Co(NH3)5SO4]Br and 0.02 mol of [Co(NH3)5Br]SO4 was prepared in 2 litre of solution. 1 litre of mixture X + excess AgNO3 $$\t... How many moles of electron weigh one kilogram? The reaction,$$3Cl{O^ - }(aq) \to ClO_3^ - (aq) + 2C{l^ - }(aq)$$is an example of : An aqueous solution of 6.3 g oxalic acid dehydrate is made up to 250ml. the volume of 0.1N NaOH required to completely neutralize 10ml of this solutio... In the standardization of Na2S2O3 using K2Cr2O7 by iodometry, the equivalent weight of K2Cr2O7 is: ... Amongst the following identify the species with an atom in +6 oxidation state The normality of 0.3 M phosphorus acid (H3PO3) is The oxidation number of sulphur in S8,S2F2,H2S respectively, are For the redox reaction:$$MnO_4^ - + {C_2}O_4^{ - 2} + {H^ + } \to M{n^{2 + }} + C{O_2} + {H_2}O$$The correct coefficients of the reactants for... The oxidation state of the most electronegative element in the products of the reaction. BaO2 with dil. H2SO4 are Read the following statement and explanation and answer as per the options given below: STATEMENT (S): In the titration of Na2CO3 with HCl using methy... The oxidation number of phosphorus in Ba(H2PO2) is : The equivalent weight of MnSO4 is half of its molecular weight, when it converts to In which mode of expression, the concentration of a solution remains independent of temperature? The brown ring complex compound is formulated as [Fe(H2O)5(NO)+]SO4. The oxidation state of iron is A molal solution is one that contains one mole of solute in The oxidation number of carbon in CH2O is If 0.50 mol of BaCl2 is mixed with 0.20 mol of Na3PO4, the maximum amount of Ba3(PO4)2 that can be formed is ... 1 mole of N2H4 loses 10 moles of electrons to form a new compound Y. assuming that all nitrogen appears in the new compound , what is the oxidation st... M is molecular weight of KMnO4. The equivalent wight of KMnO4 when it is converted into K2MnO4 is The largest number of molecules is in 2.76 g of silver carbonate on being strongly heated yields a residue weighing The total number of electrons is one molecule of carbon dioxide is A gaseous mixture contains oxygen and nitrogen in the ratio of 1 : 4 by weight. Therefore the ratio of their no of molecules is 27 g of Al will react completely with how many grams if oxygen? A compound was found to contain nitrogen and oxygen in the ratio 28 gm and 80 gm respectively. The formula of compound is ## Subjective Calculate the molarity of water if it's density is 1000 kg/m3 Hydrogen peroxide solution (20 ml) reacts quantitatively with a solution of KMnO4 solution is just decolourised by 10 ml of MnSO4 in neutral medium si... How many millilitres of 0.5 M H2SO4 are needed to dissolve 0.5 g of copper(II) carbonate? A plant virus is found to consist of uniform cylindrical particles of 150 Å in diameter and 5000 Å long. The specific volume of the virus is 0.75 cm3/... An aqueous solution containing 0.10 g KIO3 (formula weight = 214.0) was treated with an excess of KI solution. The solution was acidified with HCl. Th... A 3.00 g sample containing Fe3O4, Fe2O3 and an inert impure substance is treated with excess of KI solution in presence of dilute H2SO4. The entire ir... The composition of a sample of Wustite is Fe0.93O1.00 what percentage of the iron is present in the form of Fe(III)? 8.0575$$\times$$10-2 kg of Glauber's salt is dissolved in water to obtain 1 dm3 of a solution of density 1077.2 kg.m-3. Calculate the molarity, mola... Upon mixing 45.0 ml. of 0.25 M lead nitrate solution with 25.0 ml. of 0.10M chromic sulphate solution, precipitation of lead sulphate takes place. How... A 2.0 g sample of a mixture containing sodium carbonate, sodium bicarbonate and sodium suplphate is gently heated till the evolution of CO2 ceases. Th... One gram of commercial AgNO3 is dissolved in 50 ml. of water. It is treated with 50 ml. of a KI solution. The silver iodide thus precipitated is filte... A 1.0 g sample of Fe2O3 solid of 55.2% purity is dissolved in acid and reduced by heating the solution with zinc dust. The resultant solution is coole... A solution of 0.2 g of a compound containing Cu2+ and$$C_2O_4^{2-}$$ions on titration with 0.02M$$KMnO_4$$in presence of$$H_2SO_4$$consumes 22.... A mixture of H2C2O4 (oxalic acid) and NaHC2O4 weighing 2.02 g was dissolved in water and solution made upto one litre. Ten millilitres of the solution... A solid mixture (5.0 g) consisting of lead nitrate and sodium nitrate was headed below 600oC until the weight of the residue was constant. If the loss... Calculate the molality of 1 litre solution of 93% H2SO4 (weight/volume). The density of the solution is 1.84 g/ml An equal volume of a reducing agent is titrated separately with 1M KMnO4 in acid neutral and alkaline media. The volumes of KMnO4 required are 20 ml.... A sample of hydrazine sulphate (N2H6SO4) was dissolved in 100 ml. of water, 10 ml of this solution was reacted with excess of ferric chloride solution... A sugar syrup of weight 214.2 g contains 34.2 g of sugar (C12H22O11). Calculate (i) molal concentration and (ii) mole fraction of sugar in the syrup ... (i) What is the weight of sodium bromate and molarity pf solution necessary to prepare 85.5 ml of 0.672 B solution when the half-cell reaction is$$Br...
Complete and balance the following equation: Mn2+ + PbO2 $$\to$$ $$MnO_4^-$$ + H2O
Complete and balance the following equation: $$ClO_3^-$$ + I- + H2SO4 $$\to$$ Cl- + $$HSO_4^-$$
Complete and balance the following equation: S + OH- $$\to$$ S2- + $$S_2O_3^-$$
Complete and balance the following equation: Ag+ + AsH3 $$\to$$ H3AsO3 + H+
Arrange the following in increasing oxidation number of iodine. I2, HI, HIO4, ICl
Five ml of 8N nitric acid, 4.8ml of 5N hydrochloric acid and a certain volume of 17M sulphuric acid are mixed together and made upto 2 litre. Thirty m...
The density of a 3 M Sodium thiosulphate solution (Na2S2O3) is 1.25 g per ml. Calculate (i) the percentage by weight of sodium thiosulphate, (ii) the...
Complete and balance the following equation: $$Cr_2O_7^{2-}$$ + C2H4O $$\to$$ C2H4O2 + Cr3+...
Complete and balance the following equation: Zn + $$NO_3^- \to$$ Zn2+ + $$NH_4^+$$
Complete and balance the following equation: Ce3+ + $$S_2O_8^{-2} \to$$ $$SO_4^{-2}$$ + Ce4+
4.08 g of a mixture of BaO and an unknown carbonate MCO3 was heated strongly. The residue weighed 3.64 g. This was dissolved in 100 ml of 1 N HCl. The...
Complete and balance the following equation: HNO3 + HCl $$\to$$ NO + Cl2
Complete and balance the following equations: Cl2 + OH- $$\to$$ Cl- + ClO-
Hydroxylamine reduces iron (III) according to the equation: 2NH2OH + 4Fe3+ $$\to$$ N2O(g) $$\uparrow$$ + H2O + 4Fe2+ + 4H+ Iron (II) thus produced...
A 1.00 gm sample of H2O2 solution containing X percent H2O2 by weight requires X ml of a KMnO4 solution for complete oxidation under acidic condition...
Balance the following Equations: (i) Cu2O + H+ + $$NO_3^ - \to$$ Cu2+ + NO + H2O (ii) K4[Fe(CN)6] + H2SO4 + H2O $$\to$$ K2SO4 + FeSO4 + (NH4)2SO4 + ...
A hydrocarbon contains 10.5 g of carbon per gram of hydrogen. 1 litre of the hydrocarbon at 127oC and 1 atmosphere weighs 2.8 g. Find the molecular fo...
A mixture contains NaCl and unknown chloride MCl. (i) 1g of this is dissolved in water. Excess of acidified AgNO3 solution is added to it. 2.567 g of ...
Find (i) The total number of neutrons and (ii) The total mass of neutron in 7 mg of 14C (Assume that mass of neutron = mass of hydrogen atom)...
(a) 1 litre of a mixture of CO and CO2 is taken. This mixture is passed through a tube containing red hot charcoal. The volume now becomes 1.6 litre....
(i). A sample of MnSO4.4H2O is strongly heated in air. The residue is Mn3O4. (ii). The residue is dissolved in 100 ml of 0.1N FeSO4 containing dilute ...
(a) One litre of a sample of hard water contains 1 mg of CaCl2 and 1 mg of MgCl2. Find the total hardness in terms of parts of CaCO3 per 106 parts of ...
4.215 g of a metallic carbonate was heated in a hard glass tube and the CO2 evolved was found to measure 1336 ml at 27oC and 700 mm pressure. What is ...
(a). 5.5 g of a mixture FeSO4.7H2O and Fe2(SO4)3.9H2O requires 5.4 ml of 0.1 N KMnO4 solution for complete oxidation. Calculate the number of gram mol...
5 ml of a gas containing only carbon and hydrogen were mixed with an excess of oxygen (30 ml) and the mixture exploded by means of an electric spark. ...
In the analysis of 0.5 g sample feldspar, a mixture of chlorides of sodium and potassium is obtained which weighs 0.1180g. Subsequent treatment of mix...
Account for the following : Limit your answer to two sentences. "Atomic weights of most of the elements are fractional."
What weight of AgCl will be precipitated when a solution containing 4.77 g of NaCl is added to a solution of 5.77g of AgNO3?
One gram of an alloy of aluminium and magnetism when treated with excess of dil. HCl forms magnesium chloride, aluminium chloride and hydrogen. The e...
Igniting MnO2 converts it quantitatively to Mn3O4. A sample of pyrolusite is of the following composition : MnO2 80%, SiO2 and other inert constituent...
Naturally occurring boron consists of two isotopes whose atomic weighs are 10.01 and 11.01. The atomic weight of natural oron is 10.81. Calculate the ...

## Fill in the Blanks

The compound YBa2Cu3O7, which shows superconductivity, has copper in oxidation state ______ assume that the rare earth element yttrium is in its usua...
The weight of $$1 \times 10^{22}$$ molecules of CuSO4.5H2O is ____.
3 g of a salt of molecular weight 30 is dissolved in 250 g of water. The molality if the solution is _____.
The modern atomic unit is based on the mass of ______.
The total no of electron present in 18 ml of water is ______.
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