Some Basic Concepts in Chemistry — practice questions

188 curated practice questions from Some Basic Concepts in Chemistry (Chemistry JEE Advanced, NTA Exams) — 141 hard, 47 medium. Every question includes the final answer free; step-by-step worked solutions with a free account.

• Assertion (A) : White phosphorous reacts with aqueous caustic soda to form PH 3 and NaH 2 PO 2 . It is…
• 0.2 mole of K 3 PO 4 and 0.3 mole of BaCl 2 are mixed in 1 L of solution. Which of these is/are correct ?
• At 100°C and 1 atm, if the density of liquid water is 1.0 g cm –3 and that of water vapour is 0.0006 g cm –3 , then the…
• Which of the following statements regarding the compound A x B y is/are correct ?
• The oxidation number of cobalt in K 3 [Co(NO 2 ) 6 ] is
• The valency of carbon is generally 4, but its oxidation state may be -4, -2, 0, 2, -1 etc. In the compounds containing…
• The analytical molarity of a solution gives the total number of moles of a solute in one litre of the solution. The…
• Equal weights of methane and hydrogen are mixed in an empty container at 25 °C. The fraction of the total pressure…
• To check the principle of multiple proportions, a series of pure binary compounds (Pm Qn) were analyzed and their…
• In a chemical reaction K _ 2 Cr _ 2 O _ 7 + xH _ 2 SO _ 4 + ySO _ 2 ~K _ 2 SO _ 4 + Cr _ 2 ( SO _ 4 )_ 3 +z H _ 2 O …
• The total number of electrons present in 18 ml of water (density of water is 1 g ml -1 ) is (1980)
• A mixture of FeO and Fe 2 O 3 is completely reacted with 100 mL of 0.25 M acidified KMnO 4 solution. The resultant…
• 1 g alloy of Cu and Zn reacted with excess of di l . H 2 SO 4 to give H 2 gas which occupies 60 m l at STP. The…
• Based on the following information arrange four metals A, B, C and D in order of decreasing ability to act as reducing…
• Dissolving 120g of urea (mol. wt. 60) in 1000g of water gave a solution of density 1.15 g/mL. The molarity of the…
• When KMnO 4 reacts with acidified FeSO 4
• Which ordering of compounds is according to the decreasing order of the oxidation state of nitrogen ? (2012)
• The equivalent weight of MnSO 4 is half of its molecular weight when it converts to (1988)
• When a equimolar mixture of Cu 2 S and CuS is titrated with Ba(MnO 4 ) 2 in acidic medium, the final product’s contains…
• The reaction of white phosphorus with aqueous NaOH gives phosphine along with another phosphorus containing compound…
• An oxide of nitrogen has 30.43% nitrogen (At. wt. of N=14) and its one molecule weight 1.527 × 10 –22 g. Which of the…
• The temperature at which a real gas obeys the ideal gas laws over a wide range of pressure is
• 10 mL of 0.2 N HCl and 30 mL of 0.1 N HCl together exactly neutralises 40 mL of solution of NaOH, which is also exactly…
• The normality of 0.3 M phosphorous acid (H 3 PO 3 ) is (1999)
• A bottle of dry ammonia and a bottle of dry hydrogen chloride connected through a long tube are opened simultaneously…
• In the reaction, 2FeCl 3 + H 2 S 2FeCl 2 + 2HCl + S
• Equivalent weight = n-factor is very important in redox as well as non-redox reactions. With the help of n-factor we…
• A crystalline hydrated salt on being rendered anhydrous loses 45.6% of its weight. The percentage composition of…
• If 10 21 molecules are removed from 200mg of CO 2 , then the number of moles of CO 2 left are
• 11.4 gm of a mixture of butene, C 4 H 8 and butane C 4 H 10 , was burned in excess oxygen. 35.2 gm of CO 2 and 16.2 gm…
• Assertion : Both 138 g of K 2 CO 3 and 12 g of carbon have same number of carbon atoms. Reason : Both contains 1 g atom…
• A crystalline hydrated salt on being rendered anhydrous loses 45.6% of its weight. The percentage composition of…
• Amongst the following identify the species with an atom in +6 oxidation state.
• Given that the abundances of isotopes Fe 54 , Fe 56 and Fe 57 are 5%, 90% and 5%, respectively, the atomic mass of Fe…
• In the reaction I _ 2 + C _ 2 H _ 5 OH + O H CHI _ 3 + HCOO ^ - + H _ 2 O + I ^ - which of the following statements…
• An aqueous solution of glucose (C 6 H 12 O 6 ) is 0.01 M. To 200 mL of this solution, which of the following should be…
• For the redox reaction, MnO _ 4 ^ - + C _ 2 O _ 4 ^ 2- + H ^ + Mn ^ 2+ + CO _ 2 + H _ 2 O the correct coefficients of…
• Equivalent weight = n-factor is very important in redox as well as non-redox reactions. With the help of n-factor we…
• The next two questions deal with an experiment. An unknown metal ‘X’ is found to react spontaneously with 1.0M solution…
• The normality of 0.3 M phosphorous acid (H 3 PO 3 ) is
• Assertion (A) : F 2 does not undergo disproportionation reactions. Reason (R) : Fluorine shows only 0 and – 1 oxidation…
• A metal oxide has the formula Z 2 O 3 . It can be reduced by hydrogen to give free metal and water. 0.16 gm of the…
• A crystalline hydrated salt on being rendered anhydrous loses 45.6% of its weight. The percentage composition of…
• For one mole of a van der Waals gas when b = 0 and T = 300 K, the PV vs 1 / V plot is shown below. The value of the van…
• For the redox reaction MnO _ 4 ^ - + C _ 2 O _ 4 ^ 2- + H ^ + Mn ^ 2+ + CO _ 2 + H _ 2 O The correct coefficients of…
• Assertion : Equivalent volume of H 2 is 11.2 L at 1 atm and 273 K. Reason : 1/2 mole H 2 has produced when 1 mole of H…
• When 100 ml of 0.1 M KNO 3 , 400 ml of 0.2 M HCl and 500 ml of 0.3 M H 2 SO 4 are mixed. Then in the resulting solution
• One mole of N 2 O 4( g ) at 300 K is kept in a closed container under one atmosphere. It is heated to 600 K when 20%…
• Assertion (A) : The equivalent mass of an element is variable. Reason (R) : It depends on the valency of the element.
• Assertion : 1 Avogram is equal to 1 amu. Reason : Avogram is reciprocal of Avogadro’s number.
• 0.115 g of pure sodium metal was dissolved in 500 ml distilled water. The normality of the above solution, whose…
• In the reaction of sodium thiosulphate with I 2 in aqueous medium the equivalent weight of sodium thiosulphate is equal…
• To check the principle of multiple proportions, a series of pure binary compounds ( P m Q n ) were analyzed and their…
• The weight of 1 × 10 22 molecules of CuSO 4 . 5H 2 O is (1991)
• Assertion :- 0.1 M H 3 PO 3 (aq) solution has normality equal to 0.3N when completely reacted with NaOH. Reason : H 3…
• Which of the following reactions do not involve oxidation or reduction:
• 1 gm Mg sample is treated with 125 ml 0.1 N HCl and the excess of HCl is neutralised by 50 ml 0.5 N NaOH completely…
• Two non-reactive monoatomic ideal gases have their atomic masses in the ratio 2 : 3. The ratio of their partial…
• You are provided with 1 M solution of NaNO 3 whose density = 1.25 g/ml
• One mole of N 2 H 4 loses ten moles of electrons to form a new compound Y . Assuming that all the nitrogen appears in…
• Which of the following statements is/are correct ? The following reaction occurs : 2 Al +3 MnO CCl _ 4 + S _ 2 Cl _ 2…
• Fe 3+ is reduced to Fe 2+ by using
• Assertion (A) : MnO 2 can act as an oxidizing agent as well as reducing agent. Reason (R) : Oxidation state of Mn lies…
• The ratio of the rate of diffusion of helium and methane under identical condition of pressure and temperature will be
• 32 g of a sample of FeSO 4 .7H 2 O were dissolved in dilute sulphuric acid and water and its volume was made up to 1…
• 2.76 g of silver carbonate on being strongly heated yields a residue weighing
• Three metals of alkaline earth metal group (A, B, and C) when reacted with a fixed volume of liquid Br 2 separately…
• A bottle of H 2 O 2 is labelled as 10 vol H 2 O 2 . 112 mL of this solution of H 2 O 2 is titrated against 0.04 M…
• P and Q are two elements which forms P 2 Q 3 and PQ 2 . If 0.15 mole of P 2 Q 3 weights 15.9g and 0.15 mole of PQ 2…
• The volume strength of 1.5 N H 2 O 2 is (1990)
• The normality of 0.3 M phosphorus acid (H 3 PO 3 ) is
• The order of the oxidation state of the phosphorus atom in H _ 3 PO _ 2 , H _ 3 PO _ 4 , H _ 3 PO _ 3 , and H _ 4 P _ 2…
• The next two questions deal with an experiment. An unknown metal ‘X’ is found to react spontaneously with 1.0M solution…
• If 0.50 mol of BaCl 2 is mixed with 0.20 mol of Na 3 PO 4 , the maximum number of moles of Ba 3 (PO 4 ) 2 that can be…
• Which of the following statements is/are correct ? 20.0 mL of 6.0 M HCl is mixed with 50.0 mL of 2.0 M Ba(OH) 2 , and…
• X ml of H 2 gas effuses through a hole in a container in 5 seconds. The time taken for the effusion of the same volume…
• One mole of a monoatomic real gas satisfies the equation P ( V – b ) = RT where b is a constant. The relationship of…
• The oxidation number of phosphorus in Ba(H 2 PO 2 ) 2 is
• The reaction which proceeds in the forward direction is
• The valency of carbon is generally 4, but its oxidation state may be -4, -2, 0, 2, -1 etc. In the compounds containing…
• 20 mL of 0.2 M NaOH (aq) solution is mixed with 35 mL of 0.1 M NaOH (aq) solution and the resultant solution is diluted…
• Consider a titration of potassium dichromate solution with acidified Mohr’s salt solution using diphenylamine as…
• Equal weights of ethane and hydrogen are mixed in an empty container at 25°C. The fraction of the total pressure…
• Assertion : Number of molecules present in SO 2 is twice the number of molecules present in O 2 . Reason : Molecular…
• Assertion : When a solution is diluted from volume V 1 to V 2 by adding solvents, its molarity before dilution M 1 and…
• 500 mL of a 0.05 M Mohr salt solution required the same volume of permanganate solution for complete oxidation. Which…
• An element A in a compound ABD has oxidation number –n. It is oxidised by Cr 2 O 7 2– in acidic medium. In the…
• Equivalent weight = n-factor is very important in redox as well as non-redox reactions. With the help of n-factor we…
• For the reaction : (2016) + ClO _ 3 ^ - + H _ 2 SO _ 4 Cl ^ - + HSO _ 4 ^ - + I _ 2 The correct statement(s) in the…
• Assertion : Molality of solution is independent of temperature while mole fraction depends on temperature. Reason …
• The rate of diffusion of methane at a given temperature is twice that of a gas X . The molecular weight of X is
• Equal volumes of 0.200 M HCl and 0.400M KOH are mixed. The concentrations of the ions in the resulting solution are :
• 6.3g of oxalic acid dihydrate have been dissolved in water to obtain a 250 mL solution. How much volume of 0.1 N NaOH…
• The compressibility of a gas is less than unity at STP. Therefore,
• Which ordering of compounds is according to the decreasing order of the oxidation state of nitrogen?
• 1 mole of equimolar mixture of ferric oxalate and ferrous oxalate will require x mole of KMnO 4 in acidic medium for…
• Often more than one reaction is required to change starting materials into the desired product. This is true for many…
• When a hydrate of Na 2 CO 3 is heated until all the water is removed, it loses 54.3 per cent of its mass. The formula…
• HNO 3 used as a reagent has specific gravity of 1.42g mL – 1 and contains 70% by strength HNO 3 . Volume of water…
• The oxidation number of sulphur in S 8 , S 2 F 2 , H 2 S respectively, are (1999)
• Given that, E _ Ni ^ 2+ / Ni ^ =-0.25 ~V , E _ Cu ^ 2+ / Cu ^ =+0.34 ~V E _ Ag ^ 2+ / Ag ^ 0 =+0.80 ~V , E _ Zn ^ 2+ /…
• Which of the following solutions will exactly oxidize 25 mL of an acid solution of 0.1 M iron (II) oxalate :
• Equal weights of methane and oxygen are mixed in an empty container at 25 °C. The fraction of the total pressure…
• An aqueous solution of phosphoric acid (H 3 PO 4 ) being titrated has molarity equal to 0.25 M. Which of the following…
• Assertion : 1mole of H 2 SO 4 is neutralised by 2 moles of NaOH but 1 equivalent of H 2 SO 4 is neutralised by 1…
• On the left column, some reactions are indicated and on the right column, properties of reactions are described. Match…
• In a metal deficient oxide sample, M x Y 2 O 4 (M and Y are metals), M is present in both +2 and +3 oxidation states…
• For the reaction : I – + ClO 3 – + H 2 SO 4 → Cl – + HSO 4 – + I 2 The incorrect statement in the balanced equation is
• Assertion : In laboratory, reagents are made to a specific molarity rather molality. Reason : The volume of sulution is…
• An aqueous solution of 6.3 g oxalic acid dihydrate is made up to 250 mL. The volume of 0.1 N NaOH required to…
• Standard electrode potential data are useful for understanding the suitability of an oxidant in a redox titration. Some…
• NH 3 is formed in the following steps : I. Ca + 2C → CaC 2 50% yield II. CaC 2 + N 2 → CaCN 2 + C 100% yield III. CaCN…
• Identify the correct statements with reference to the given reaction, P _ 4 +3 OH ^ - + H _ 2 O PH _ 3 +3 H _ 2 PO _ 2…
• Zinc sulphate contains 22.65% Zn and 43.9% H 2 O. If the law of constant proportions is true, then the mass of zinc…
• In the following reaction : Cr(OH) 3 + OH – + IO 3 – → CrO 4 2– + H 2 O + I –
• According to Graham’s law, at a given temperature the ratio of the rates of diffusion of gases A and B is given by
• The oxidation number of sulphur in S 8 , S 2 F 2 , H 2 S respectively, are
• The sulphate of a metal M contains 9.87% of M. This sulphate is isomorphous with ZnSO 4 .7H 2 O. The atomic weight of M…
• Calorie is defined as the amount of heat required to raise temperature of 1 g of water by 1°C and it is defined under…
• The equivalent weight of MnSO 4 is half its molecular weight when it is converted to
• Assertion : For a binary solution of two liquids, A and B, with the knowledge of density of solution, molarity can be…
• Which of the following volume ( V )-temperature ( T ) plots represents the behaviour of one mole of an ideal gas at one…
• For the redox reaction: MnO _ 4 ^ - + C _ 2 O _ 4 ^ 2- + H ^ + Mn ^ 2+ + CO _ 2 + H _ 2 O the correct coefficients of…
• Often more than one reaction is required to change starting materials into the desired product. This is true for many…
• In the reaction between SO 2 and O 3 , the equivalent weight of ozone is :
• In the reaction, 8 Al +3 Fe _ 3 O _ 4 4 Al _ 2 O _ 3 +9 Fe , the number of electrons transferred from reductant to…
• The analytical molarity of a solution gives the total number of moles of a solute in one litre of the solution. The…
• The given graph represents the variation of Z (compressibility factor = ) versus P , for three real gases A , B and C …
• Given that the abundances of isotopes 54 Fe, 56 Fe and 57 Fe are 5%, 90% and 5% respectively, the atomic mass of Fe is
• Assertion (A) : KO 2 is superoxide. Reason (R) : Oxidation state of oxygen of KO 2 is – 2 .
• 1 mole of oxalic acid is treated with conc. H 2 SO 4 . The resultant gaseous mixture is passed through a solution of…
• The mole fraction of NaCl in aqueous solution is 0.2 . The solution is
• BrO _ 3 ^ (1) +5 Br ^ (2) Br _ 2 +3 H _ 2 O 1f 50 ml of 0.1M BrO _ 3 ^ is mixed with 30 ml of 0.5 M Br ^ solution that…
• When the same amount of zinc is treated separately with excess of sulphuric acid and excess of sodium hydroxide, the…
• How much NaNO 3 must be weighed out to make 50 ml of an aqueous solution containing 70 mg of Na + per m l ?
• 125 mL of 63% (w/v) H 2 C 2 O 4 . 2H 2 O solution is made to react with 125 mL of a 40% (w/v) NaOH solution. The…
• For the reaction H 3 PO 4 + Ca(OH) 2 CaHPO 4 + 2 H 2 O 1 mol 1 mol Which are true statements?
• If Sn ^ 2+ +2 e ^ - Sn ; E ^ 0 =-0.14 ~V Sn ^ 4+ +2 e ^ - Sn ^ 2+ E ^ 0 =+0.13 ~V then:
• Redox reactions play a pivotal role in chemistry and biology. The values of standard redox potential ( E °) of two…
• The number of moles of KMnO 4 that will be needed to react completely with one mole of ferrous oxalate in acidic medium…
• If 100 m l of H 2 SO 4 (A) and 100 m l of H 2 O (B) are mixed. Then the mass per cent of H 2 SO 4 would be (Given…
• The density of a solution of H 2 SO 4 is 1.84 gm/ml and it contain 93% H 2 SO 4 by volume. Then
• Assertion (A): In the titration of Na 2 CO 3 with HCl using methyl orange indicator, the volume required at the…
• A compound possesses 8% sulphur by mass. The least molecular mass is
• HNO 3 used as a reagent has specific gravity of 1.42g mL – 1 and contains 70% by strength HNO 3 . Volume of acid that…
• The number of moles of KMnO 4 that will be needed to react with one mole of sulphite ion in acidic solution (1997)
• The number of moles of KMnO 4 that will be needed to react completely with one mole of ferrous oxalate in acidic…
• Two elements X and Y have atomic weights of 14 and 16. They form a series of compounds A, B, C D and E in which for the…
• The vapour density of a chloride of an element is 39.5. The Ew of the elements is 3.82. The atomic weight of the…
• 25 mL of 0.5 M H 2 O 2 solution is added to 50 mL of 0.2 M KMnO 4 in acid solution. Which of the following statements…
• If 100 mL of H 2 SO 4 and 100 mL of H 2 O are mixed, the mass percent of H 2 SO 4 in the resulting solution is ( d _ H…
• HNO 3 used as a reagent has specific gravity of 1.42g mL – 1 and contains 70% by strength HNO 3 . Normality of acid is.
• If 0.5 mol of BaCl 2 is mixed with 0.2 mol of Na 3 PO 4 , the maximum number of moles of Ba 3 (PO 4 ) 2 that can be…
• A gaseous mixture contains oxygen and nitrogen in the ratio of 1 : 4 by weight. Therefore, the ratio of their number of…
• When Cl 2 reacts with aqeous NaOH in cold condition then oxidation number of chlorine changes from 0 to:
• An aqueous solution of 6.3g of a hydrated oxalic acid (H 2 C 2 O 4 .xH 2 O) is made up to 250 mL. The 40 mL of 0.10 N…
• Potassium combines with two isotopes of chlorine ( 35 Cl and 37 Cl) respectively to form two samples of KCl. Their…
• Assertion (A) : If 1.50 mol of KMnO 4 is required for oxidation in acidic medium, 2.50 mol of KMnO 4 would be required…
• The analytical molarity of a solution gives the total number of moles of a solute in one litre of the solution. The…
• If we consider that 1/6 in place of 1/12, mass of carbon atom is taken to be the relative atomic mass unit, the mass of…
• In the preparation of iron from haematite (Fe 2 O 3 ) by the reaction with carbon Fe _ 2 O _ 3 + C Fe + CO _ 2 How much…
• The oxidation number of carbon in CH 2 O is
• How many moles of ferric alum (NH 4 ) 2 SO 4 Fe 2 (SO 4 ) 3 .24H 2 O can be made from the sample of Fe containing…
• Many elements have non-integral atomic masses because
• 3 g of a hydrocarbon on combustion in excess of oxygen produces 8.8g of CO 2 and 5.4 g of H 2 O. The data illustrates…
• Often more than one reaction is required to change starting materials into the desired product. This is true for many…
• Assertion : Molality and mole fraction units of concentration do not change with temperature. Reason : These…
• In van der Waals equation of state for a non-ideal gas, the term that accounts for intermolecular forces is
• Mixture X = 0.02 mole of [Co(NH 3 ) 5 SO 4 ] Br and 0.02 mole of [Co(NH 3 ) 5 Br] SO 4 was prepared in 2 L solution. 1…
• X and Y are two volatile liquids with molar weights of 10 g mol –1 and 40 g mol –1 respectively. Two cotton plugs, one…
• Which of the following can act both as an oxidising as well as reducing agent :
• Consider a titration of potassium dichromate solution with acidified Mohr’s salt solution using diphenylamine as…
• A solution of NaOH is prepared by dissolving 4.0 g of NaOH in 1 L of water. Calculate the volume of the HC l gas at stp…
• 100 mL of mixture of NaOH and Na 2 SO 4 is neutralised by 10 mL of 0.5 M H 2 SO 4 . Hence, NaOH in 100 mL solution is
• Which of the following statements is/are correct ? 1.0g mixture of CaCO 3 (s ) and glass beads liberate 0.22g of CO 2…
• The valency of carbon is generally 4, but its oxidation state may be -4, -2, 0, 2, -1 etc. In the compounds containing…
• 10 mL of N/2 HCl, 20 mL of N/2 H 2 SO 4 and 30 mL N/3 HNO 3 are mixed together and solution made to one litre. The…
• To 1 L of 1.0 M impure H 2 SO 4 sample, 1.0 M NaOH solution was added and a plot was obtained as follows : The % purity…
• In the standardization of Na 2 S 2 O 3 using K 2 Cr 2 O 7 by iodometry, the equivalent weight of K 2 Cr 2 O 7 is
• In a metal deficient oxide sample, M X Y 2 O 4 ( M and Y are metals), M is present in both +2 and +3 oxidation states…
• One part of an element A combines with two parts of B (another element). Six parts of element C combine with four parts…
• Consider the given reversible reaction at equilibrium 2NO + Cl 2 → 2ClNO(g) Suppose that 0.30 mol NO, 0.20 mole of Cl 2…
• The reaction, 3 ClO ( aq )^ - ClO _ 3 ( aq )^ - +2 Cl ( aq )^ - is an example of (2001)
• The reaction, 3ClO – ( aq ) → ClO – 3( aq ) + 2Cl – ( aq ) is an example of
• Among the following, the species in which the oxidation number of an element is +6 (2000)
• At room temperature, disproportionation of an aqueous solution of in situ generated nitrous acid (HNO 2 ) gives the…
• An aqueous solution of 6.3 g oxalic acid dihydrate is made up to 250 mL. The volume of 0.1 N NaOH required to…
• In the standardization of Na 2 S 2 O 3 and K 2 Cr 2 O 7 by iodometry, the equivalent weight of K 2 Cr 2 O 7 is (2000)

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