The number of moles of oxygen in 1 L of air containing 21% oxygen by volume, in standard conditions, is [CBSE PMT 1995; Pb. PMT 2004]

Question: The number of moles of oxygen in 1 L of air containing 21% oxygen by volume, in standard conditions, is [CBSE PMT 1995; Pb. PMT 2004]

(a) 0.186 mol

(b) 0.21 mol

(c) 2.10 mol

(d) 0.0093 mol

Correct Answer: (d) 0.0093 mol

More Question

1. In the following reaction, which choice has value twice that of the equivalent mass of the oxidising agent SO₂ + H₂O → 3S + 2H₂O [DPMT 2000]
2. Complete combustion of 0.858 g of compound X gives 2.63 g of CO₂ and 1.28 g of H₂O. The lowest molecular mass X can have [Kerala MEE 2000]
3. The mass of 112 cm³ of CH₄ gas at STP is [Karnataka CET 2001]
4. What volume of Hydrogen gas, at 273 K and 1 atm pressure will be consumed in obtaining 21.6 g of elemental boron (atomic mass = 10.8) from the reduction of boron trichloride by Hydrogen [AIEEE 2003]
5. A 100 ml solution of 0.1 n HCl was titrated with 0.2 N NaOH solution. The titration was discontinued after adding 30 ml of NaOH solution. The remaining titration was completed by adding 0.25 N KOH solution. The volume of KOH required for completing the titration is [DCE 1999]
6. 3.92 g of ferrous ammonium sulphate crystals are dissolved in 100 ml of water, 20 ml of this solution requires 18 ml of KMnO₄ during titration for complete oxidation. The weight of KMnO4 present in one litre of the solution is [Tamilnadu CET 2002]
7. In standardization of Na₂S₂O₃ using K₂Cr₂O₇ by iodometry, the equivalent weight of K₂Cr₂O₇ is [IIT 2000]
8. One litre hard water contains 12.00 mg Mg^2+ milli equivalent of washing soda required to remove its hardness is
9. The set of numerical coefficient that balances the equation K₂CrO₄ + HCl → K₂Cr₂O₇ + KCl + H₂O is [Kerala CEE 2001]
10. If 10²¹ molecules are removed from 200mg of CO₂, then the number of moles of CO₂ left are [IIT 1983]
11. In a mole of water vapour at STP, the volume actually occupied or taken by the molecules (i.e., Avogadro’s No. x Volume of one molecule) is [Kerala EEE 2000]