JEE Main PYQs — Some Basic Concepts (Mole Concept)

Compounds that should not be used as primary standards in titrimetric analysis are: A. Na2Cr2O7 B. Oxalic acid C. NaOH D. FeSO4.6H2O E. Sodium tetraborate Choose the most appropriate answer from the…

In Dumas' method for estimation of nitrogen, 0.4 g of an organic compound gave 60 mL of nitrogen collected at 300 K temperature and 715 mm Hg pressure. The percentage composition of nitrogen in the…

Mass of magnesium required to produce 220 mL of hydrogen gas at STP on reaction with excess of dil. HCl is: (Given: Molar mass of Mg is 24 g mol-1)

CaCO3(s) + 2HCl(aq) -> CaCl2(aq) + CO2(g) + H2O(l) What mass of CaCl2 will be formed if 250 mL of 0.76 M HCl reacts with 1000 g of CaCO3? (Given: Molar mass of Ca, C, O, H and Cl are 40, 12, 16, 1…

On complete combustion 1.0 g of an organic compound (X) gave 1.46 g of CO2 and 0.567 g of H2O. The empirical formula mass of compound (X) is ________ g. (Given molar mass: C: 12, H: 1, O: 16)

In Dumas' method for estimation of nitrogen, 0.5 gram of an organic compound gave 60 mL of nitrogen collected at 300 K temperature and 715 mm Hg pressure. The percentage composition of nitrogen in…

Choose the correct statements: (A) Weight of a substance is the amount of matter present in it. (B) Mass is the force exerted by gravity on an object. (C) Volume is the amount of space occupied by a…

At the sea level, the dry air mass percentage composition is given as nitrogen gas: 70.0, oxygen gas: 27.0 and argon gas: 3.0. If total pressure is 1.15 atm, then calculate the ratio of followings…

Among 10-9 g (each) of the following elements, which one will have the highest number of atoms? Element: Pb, Po, Pr and Pt

Concentrated nitric acid is labelled as 75% by mass. The volume in mL of the solution which contains 30 g of nitric acid is ______. Given: Density of nitric acid solution is 1.25 g/mL (a) 45 (b) 55…

Which of the following linear combination of atomic orbitals will lead to formation of molecular orbitals in homonuclear diatomic molecules (internuclear axis in z-direction)? A. 2pz and 2px B. 2s…

Which of the following statement is true with respect to H2O, NH3 and CH4? A. The central atoms of all the molecules are sp3 hybridized. B. The H–O–H, H–N–H and H–C–H angles in the above molecules…

On combustion 0.210 g of an organic compound containing C, H and O gave 0.127 g H2O and 0.307 g CO2. The percentages of hydrogen and oxygen in the given organic compound respectively are:

Molality (m) of 3\,M aqueous solution of NaCl is: (Density = 1.25\,g mL-1; Mr: Na = 23, Cl = 35.5)

The density of "x M" solution of NaOH is 1.12\,g mL-1, while in molality, the concentration of the solution is 3\,m (3 molal). Then x is: (Molar mass of NaOH = 40\,g/mol)

An organic compound has 42.1\% carbon, 6.4\% hydrogen and remainder is oxygen. If its molecular weight is 342, then its molecular formula is:

The number of moles of methane required to produce 11\,g of CO2(g) after complete combustion is: (Molar mass of methane = 16\,g/mol)

Combustion of glucose (C6H12O6) produces CO2 and water. The amount of oxygen (in g) required for complete combustion of 900\,g of glucose is: [Molar mass of glucose = 180\,g/mol]

A sample of CaCO3 and MgCO3 weighed 2.21\,g is ignited to constant weight of 1.152\,g. The composition of the mixture is: (Mr: CaCO3=100, MgCO3=84)

Which of the following have the same number of significant figures? (A) 0.00253 (B) 1.0003 (C) 15.0 (D) 163 Choose the correct answer:

The number of molecules and moles in 2.8375 litres of O2 at STP are respectively:

A solution is prepared by adding 2\,g of X to 1 mole of water. Mass percent of X in solution is:

When a hydrocarbon A undergoes combustion in the presence of air, it requires 9.5 equivalents of oxygen and produces 3 equivalents of water. What is the molecular formula of A?

Assertion A: 3.1500\,g of hydrated oxalic acid dissolved in water to make 250.0\,mL solution will result in 0.1\,M oxalic acid solution. Reason R: Molar mass of hydrated oxalic acid is 126\,g mol-1.…

A metal chloride contains 55.0\% of chlorine by weight. 100\,mL vapours at STP weigh 0.57\,g. The molecular formula of the metal chloride is: (At. mass Cl = 35.5\,u)

25\,mL of 1\,M AgNO3 is added to 25\,mL of 1.05\,M KI solution. The ion(s) present in very small quantity in the solution is/are:

When hydrocarbon A undergoes complete combustion it requires 11 equivalents of O2 and produces 4 equivalents of water. Molecular formula of A is:

Using the rules for significant figures, the correct answer for the expression 0.02858 0.1120.5702 will be:

A commercially sold conc. HCl is 35\% HCl by mass. If the density of this commercial acid is 1.46\,g/mL, the molarity of this solution is: (Atomic mass: Cl = 35.5, H = 1\,amu)

Hemoglobin contains 0.34\% of iron by mass. The number of Fe atoms in 3.3\,g of hemoglobin is: (Atomic mass of Fe = 56\,u, NA = 6.022 1023\,mol-1)

Consider the reaction: 4HNO3(l) + 3KCl(s) -> Cl2(g) + NOCl(g) + 2H2O(g) + 3KNO3(s) The amount of HNO3 required to produce 110.0\,g of KNO3 is: (Atomic masses: H = 1, O = 16, N = 14, K = 39)

SO2Cl2 + 2H2O -> H2SO4 + 2HCl. 16 moles of NaOH is required for complete neutralisation of the resultant acidic mixture. The number of moles of SO2Cl2 used is:

250\,g solution of D-glucose in water contains 10.8\% carbon by weight. The molality of the solution is nearest to: (H=1, C=12, O=16)

If a rocket runs on fuel C15H30 and liquid oxygen, the weight of O2 required and CO2 released for every litre of fuel are: (density =0.756\,g/mL)

120\,g of an organic compound (only C and H) gives 330\,g CO2 and 270\,g H2O on combustion. % of C and H respectively are:

Compound A: 8.7\% H, 74\% C, 17.3\% N; molar mass =162\,g/mol. Molecular formula is: (C=12, H=1, N=14)

Production of Fe in blast furnace: Fe3O4(s)+4CO(g)->3Fe(l)+4CO2(g). When 4.640\,kg of Fe3O4 and 2.520\,kg of CO are allowed to react, the amount of iron (in g) produced is: (MFe=56, MO=16, MC=12)

N2(g) + 3H2(g) <=> 2NH3(g); 20 g N2 reacts with 5 g H2. The limiting reagent and moles of NH3 formed are:

Complete combustion of 1.80\,g of an oxygen containing compound (CxHyOz) gave 2.64\,g of CO2 and 1.08\,g of H2O. The percentage of oxygen in the organic compound is:

Amongst the following statements, that which was not proposed by Dalton was:

The average molar mass of chlorine is 35.5\,g mol-1. The ratio of 35Cl to 37Cl in naturally occurring chlorine is close to:

The strengths of 5.6 volume hydrogen peroxide (density 1\,g/mL) in terms of mass percentage and molarity (M) respectively are: (Molar mass of H2O2=34\,g/mol)

A solution of two components containing n1 moles of 1st component and n2 moles of 2nd component. M1, M2 are molecular weights. If d is density in g/mL, C2 is molarity and x2 is mole fraction of 2nd…

The first and second ionisation enthalpies of a metal are 496 and 4560\,kJ mol-1, respectively. How many moles of HCl and H2SO4, respectively, will be needed to react completely with 1 mole of the…

The NH3 released on quantitative reaction of 0.6 g urea (NH2CONH2, MW=60) with NaOH can be neutralized by:

The percentage composition of carbon by mole in methane (CH4) is:

5 moles of AB2 weigh 125 10-3\,kg and 10 moles of A2B2 weigh 300 10-3\,kg. The molar masses MA and MB in kg mol-1 are:

The minimum amount of O2(g) consumed per gram of reactant is for the reaction: (Atomic mass: Fe = 56, O = 16, Mg = 24, P = 31, C = 12, H = 1)

What would be the molality of 20\% (mass/mass) aqueous solution of KI? (Molar mass of KI = 166\,g/mol)

25\,mL of the given HCl solution requires 30\,mL of 0.1\,M sodium carbonate solution. What is the volume of this HCl solution required to titrate 30\,mL of 0.2\,M aqueous NaOH solution?

8\,g of NaOH is dissolved in 18\,g of H2O. Mole fraction of NaOH in solution and molality (in mol/kg) of the solution respectively are:

0.27\,g of a long chain fatty acid was dissolved in 100\,cm3 of hexane. 10\,mL of this solution was added dropwise to the surface of water in a round watch glass. Hexane evaporates and a monolayer is…

For the reaction N2(g) + 3H2(g) -> 2NH3(g), identify dihydrogen (H2) as a limiting reagent in the following reaction mixtures:

At 300 K and 1 atmospheric pressure, 10 mL of a hydrocarbon required 55 mL of O2 for complete combustion, and 40 mL of CO2 is formed. The formula of the hydrocarbon is:

25 g of an unknown hydrocarbon upon burning produces 88 g of CO2 and 9 g of H2O. This unknown hydrocarbon contains:

For the following reaction, the mass of water produced from 445\,g of C57H110O6 is: 2C57H110O6 + 163O2 -> 114CO2 + 110H2O

A 10 mg effervescent tablet releases 0.25 mL of CO2 at 298.15 K and 1 bar (molar volume=25.0 L). What is the percentage of NaHCO3 in the tablet? [Mr(NaHCO3)=84]