1 mole of PbS is oxidised by " X " moles of O₃ to get " Y " moles of O₂ · X+Y=

Volume of 3 MNaOH (formula weight 40 g mol⁻¹ ) which can be prepared from 84 g of NaOH is × 10⁻¹ dm³.

Mass of methane required to produce 22 g of CO₂ after complete combustion is g. (Given Molar mass in g mol⁻¹) C = 12.0 H = 1.0 O = 16.0

A solution of H₂ SO₄ is 31.4 % H₂ SO₄ by mass and has a density of 1.25 g / mL. Ine molarity of the H₂ SO₄ solution is M (nearest integer) [Given molar mass of H₂ SO₄=98 g mol⁻¹ ]

Molality of 0.8 MH₂ SO₄ solution (density 1.06 g cm⁻³ ) is × 10⁻³ m.

The mass of sodium acetate (CH₃ COONa) required to prepare 250 mL of 0.35 M aqueous solution is ____ g. (Molar mass of CH₃ COONa is 82.02 g mol⁻¹ ) □

0.05 cm thick coating of silver is deposited on a plate of 0.05 m² area. The number of silver atoms deposited on plate are ____ × 10²³. (At mass Ag=108, d=7.9 g cm⁻³ )

If a substance ^′ A ' dissolves in solution of a mixture of ^′ B ' and ^′ C ' with their respective number of moles as n_A, n_B and n_C, mole fraction of C in the solution is:

Number of moles of methane required to produce 22 gCO_{2( g)} after combustion is x × 10⁻² moles. The value of x is

The molarity of 1 L orthophosphoric acild (H₃ PO₄) having 70 % purity by weight (specific gravity 1.54 g cm⁻³ ) is ____ M.

A sample of CaCO₃ and MgCO₃ weighed 2.21 g is ignited to constant weight of 1.152 g . The composition of mixture is: (Given molar mass in gmol ⁻¹ CaCO₃: 100, MgCO₃: 84 )

Consider the following reaction: 3 PbCl₂+2(NH₄)₃ PO₄ → Pb₃(PO₄)₂+6 NH₄ Cl If 72 mmol of PbCl₂ is mixed with 50 mmol of (NH₄)₃ PO₄, then amount of Pb₃(PO₄)₂ formed is ____ mmol. (nearest integer)

10 mL of gaseous hydrocarbon on combustion gives 40 mL of CO₂( g) and 50 mL of water vapour. Total number of carbon and hydrogen atoms in the hydrocarbon is

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

Combustion of glucose (C₆ H₁₂ O₆) produces CO₂ and water. The amount of oxygen (in g ) required for the complete combustion of 900 g of glucose is: [Molar mass of glucose in gmol ⁻¹=180 ]

Molarity (M) of an aqueous solution containing xg of anhyd. CuSO₄ in 500 mL solution at 32^° C is 2 × 10⁻¹ M. Its molality will be ____ × 10⁻³ m (nearest integer). [Given density of the solution =1.25 g / mL.]

Given below are two statements : Statement I : One mole of propyne reacts with excess of sodium to liberate half a mole of H² gas. Statement II: Four g of propyne reacts with NaNH₂ to liberate NH₃ gas which occupies 224 mL at STP. In the light of the above statements, choose the most appropriate answer from the options given below :

20 mL of 2 M NaOH solution is added to 400 mL of 0.5 M NaOH solution. The final concentration of the solution is ____ × 10⁻² M. (Nearest integer)

2.8× 10⁻³ mol of CO₂ is left after removing 10²¹ molecules from its 'X' mg sample. The mass of CO₂ taken initially is Given: N_A=6.02× 10²³ mol⁻¹

When 81.0 g of aluminium is allowed to react with 128.0 g of oxygen gas, the mass of aluminium oxideproduced in grams is ____ (Nearest integer) Given : Molar mass of AI is 27.0 g mol⁻¹ Molar mass of O is 16.0 g mol⁻¹

0.01 mole of an organic compound (X) containing 10 % hydrogen, on complete-combustion produced0.9 gH₂ O. Molar mass of (X) is ____ gmol⁻¹.

Xg of benzoic acid on reaction with aq NaHCO₃ released CO₂ that occupied 11.2 L volume at STP. X is ________ g.

Consider the following reaction occurring in the blast furnace: Fe₃O_{4( s)} + 4CO_(g) → 3Fe_(l) + 4CO_{2( g)} 'x' kg of iron is produced when 2.32 × 10³ kgFe₃O₄ and 2.8 × 10² kgCO are brought together in the furnace. The value of 'x' is________ . (nearest integer) Given: molar mass of Fe₃O₄ = 232 g mol ^{− 1} molar mass of CO = 28 g mol ^{− 1} molar mass of Fe = 56 g mol ^{− 1}

The elemental composition of a compound is 54.2 % C, 9.2 % H and 36.6 % O. If the molar mass of the compound is 132 g₁₃ mol⁻¹, the molecular formula of the compound is : [Given : The relative atomic mass of C: H: O=12: 1: 16 ]

Quantitative analysis of an organic compound (X) shows following % composition. C : 14.5% Cl : 64.46% H: 1.8% (Empirical formula mass of the compound (X) is ____ × 10⁻¹ (Given molar mass in gmol⁻¹ of C:12,H:1,O:16,Cl:35.5)

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.

0.1 mol of the following given antiviral compound (P) will weigh _____ × 10⁻¹g (nearest integer). The structure of compound (P) is shown in the figure: a 5-iodo-uracil base joined to a 2'-fluoro furanose sugar.

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 ____ (Given molar mass in gmol⁻¹C:12,H:1,O:16)

CaCO₃(s) + 2HCl(aq) → CaCl₂(aq) + CO₂(g) + H₂O(l) Consider the above reaction, 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 and 35.5gmol ^{− 1}, respectively)

Consider the above sequence of reactions. 151 g of 2-bromopentane is made to react. Yield of major product P is 80 % whereas Q is 100 %. Mass of product Q obtained is ____ g. (Given molar mass in gmol⁻¹ H: 1, C: 12, O: 16, Br: 80 ) Reaction sequence: 2-bromopentane CH₃-CH₂-CH₂-CHBr-CH₃ → (alcoholic KOH) P (major product) → (Br₂) Q.

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 the compound (Aqueous tension at 300 K=15 mm Hg ) is ____ %

0.5 g of an organic compound on combustion gave 1.46 g of CO₂ and 0.9 g of H₂O. The percentage of carbon in the compound is _____ . (Nearest integer) [Given : Molar mass ( in. gmol ^{− 1} ) . C:12,H:1,O:16]

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

Xg of nitrobenzene on nitration gave 4.2 g of m -dinitrobenzene. X= ____ g. (nearest integer) [Given : molar mass (in gmol ⁻¹ ) C: 12, H: 1, O: 16, N: 14 ]

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.

10 mL of 2 M NaOH solution is added to 20 mL of 1 M HCl solution kept in a beaker. Now, 10 mL of this mixture is poured into a volumetric flask of 100 mL containing 2 moles of HCl and made the volume upto the mark with distilled water. The solution in this flask is :

Fortification of food with iron is done using FeSO₄ · 7H₂O . The mass in grams of the FeSO₄. 7H₂O required to achieve 12 ppm of iron in 150 kg of wheat is ___________ (Nearest integer) [Given: Molar mass of Fe,S and O respectively are 56, 32 and 16 g mol ^{− 1}]

Thyroxine, the hormone has given below structure The percentage of iodine in thyroxine is ____%. (nearest integer) (Given molar mass in gmol⁻¹C:12,H:1,O:16, N:14,I:127) The structure of thyroxine is shown in the figure: C₁₅H₁₁I₄NO₄, two iodinated phenyl rings joined by an ether oxygen.

An organic compound weighing 500 mg, produced 220 mg ofCO₂, on complete combustion. The percentage composition of carbon in the compound is ____%. (nearest integer) (Given molar mass in gmol⁻¹ of C:12,O:16)

On combustion 0.210 g of an organic compound containing C, H and O gave 0.127 gH₂ O and 0.307 gCO₂ . The percentages of hydrogen and oxygen in the given organic compound respectively are:

14.0 g of calcium metal is allowed to react with excess HCl at 1.0 atm pressure and 273 K . Which of the following statements is incorrect? [Given : Molar mass in gmol ⁻¹ of Ca-40, Cl-35.5, H-1 ]

80 mL of a hydrocarbon on mixing with 264 mL of oxygen in a closed U-tube undergoes complete combustion. The residual gases after cooling to 273 K occupy 224 mL . When the system is treated with KOH solution, the volume decreases to 64 mL . The formula of the hydrocarbon is:

In the reaction, 2 Al(s)+6 HCl(aq) → 2 Al³⁺(aq)+6 Cl⁻(aq)+3 H₂( g)

A+2 B → AB₂ 36.0 g of 'A' (Molar mass: 60 g mol⁻¹ ) and 56.0 g of 'B' (Molar mass: 80 g mol⁻¹ ) are allowed to react. Which of the following statements are correct ? A. ' A ' is the limiting reagent. B. 77.0 g of AB₂ is formed. C. Molar mass of A B₂ is 140 g mol⁻¹. D. 15.0 g of A is left unreacted after the completion of reaction. Choose the correct answer from the options given below i

At T(K), 100 g of 98 % H₂ SO₄(w / w) aqueous solution is mixed with 100 g of 49 % H₂ SO₄(w / w) aqueous solution. What is the mole fraction of H₂ SO₄ in the resultant solution? (Given : Atomic mass H=1 u ; S=32 u ; O=16 u ). (Assume that temperature after mixing remains constant)

x mg of pure HCl was used to make an aqueous solution. 25.0 mL of 0.1 MBa(OH)₂ solution is used when the HCl solution was titrated against it. The numerical value of x is ____ × 10⁻¹. (Nearest integer) Given: Molar mass of HCl and Ba(OH)₂ are 36.5 and 171.0 g mol⁻¹ respectively.

X and Y are the number of electrons involved, respectively during the oxidation of I⁻to I₂ and S²⁻ to S by acidified K₂ Cr₂ O₇. The value of X+Y is ____。

One mole of Cl₂( g) was passed into 2 L of cold 2 M KOH solution. After the reaction, the concentrations of Cl⁻, ClO⁻and OH⁻are respectively (assume volume remains constant)

0.53 g of an organic compound (x) when heated with excess of nitric acid (concentrated) and then with silver nitrate gave 0.75 g of silver bromide precipitate. 1.0 g of (x) gave 1.32 g of CO₂ gas on combustion. The percentage of hydrogen in the compound (x) is ____ %. [Nearest Integer] [Given: Molar mass in gmol ⁻¹ H: 1, C: 12, Br: 80, Ag: 108, O: 16_{; Compound} (x): C_x H_y Br₂ ]

For the given reaction; CaCO₃+2 HCl → CaCl₂+H₂ O+CO₂ If 90 gCaCO₃ is added to 300 mL of HCl which contains 38.55 % HCl by mass and has density 1.13 g mL⁻¹, then which of the following option is correct ? Given molar mass of H, Cl, Ca and O are 1,35.5,40 and 16 g mol⁻¹ respectively.

One mole of an alkane (x) requires 8 mole oxygen for complete combustion. Sum of number of carbon and hydrogen atoms in the alkane (x) is ____。

The mass of iron converted into Fe₃ O₄ by the action of 18 g of steam is : (Given : Molar mass of H, O and Fe are 1, 16 and 56 g mol⁻¹ respectively) Assume iron is present in excess :

Complete combustion of Xg of an organic compound gave 0.25 g of CO₂ and 0.12 g of H₂ O. If the % of carbon is 25 % and of hydrogen is 4.89 %, then X= ____ × 10⁻³ g. (Nearest integer) (Molar mass of C, H and O are 12,1 and 16 g mol⁻¹ respectively.)

The ratio of mass percentage (w / w) of C: H in a hydrocarbon is 12: 1. It has two carbon atoms. The weight (in g ) of CO₂( g) formed when 3.38 g of this hydrocarbon is completely burnt in oxygen is :(. Given : Molar mass in gmol .⁻¹ C: 12, H: 1, O: 16)

Number of moles and number of molecules in 1.4187 L of SO₂ at STP respectively are

The correct order of total number of atoms present in (A) 2 moles of cyclohexane (B) 684 g of sucrose (C) 90.8 L of dihydrogen at STP is :

What is the mole fraction of water in 10 % by weight (w / w) of aqueous urea solution? [Given: Molar mass of H, O, C and N are 1,16,12 and 14 g mol⁻¹ respectively.]

How many grams of residue is obtained by heating 2.76 g of silver carbonate? (Given : Molar mass of C, O and Ag are 12,16 and 108 g mol⁻¹ respectively)

What volume of hydrogen gas at STP would be liberated by action of 50 mL of H₂ SO₄ of 50 % purity (density =1.3 g mL⁻¹ ) on 20 g of zinc? Given : Molar mass of H, O, S, Zn are 1,16,32,65 g mol⁻¹ respectively.

An oxide of iron contains 69.9 % iron, its empirical formula, is: (Given : Molar mass of Fe and O are 56 and 16 g mol⁻¹ respectively.)

Which of the following contain the same number of atoms? (Given : Molar mass in gmol⁻¹ of H, He, O and S are 1,4,16 and 32 respectively) Items to compare: A. 2 g of O₂ gas; B. 4 g of SO₂ gas; C. 1400 mL of O₂ at STP; D. 0.05 L of He at STP; E. 0.0625 mol of H₂ gas.

Match List - I with List - II. List I (mass of substance): A. 1.8 mg water; B. 9.8 mg sulphuric acid; C. 1.8 mg carbon; D. 5.85 mg salt (NaCl). List II (number of atoms): I. 2 × 10⁻⁴ × N_A; II. 1.5 × 10⁻⁴ × N_A; III. 3 × 10⁻⁴ × N_A; IV. 7 × 10⁻⁴ × N_A.