NEET Chemistry - Mole concept

What volume of oxygen gas (O2) is required to completely burn 2L of propane (C3H8) measured under the same conditions?

• 7L

• 6L

• 5L

• 10L

The number of moles of (KMnO4) reduced by one mole of (KI) in an alkaline medium is:

• One fifth

• Five

• One

• Two

The number of moles of oxygen in 1L of air containing 21% oxygen by volume, under standard conditions, is:

• 0.0093 mole

• 2.10 moles

• 0.186 mole

• 0.21 mole

The number of atoms in 0.5 moles of aluminium (Atomic mass = 27 u) is:

• 3.01 x 10^23 atoms

• 6.02 x 10^23 atoms

• 9.03 x 10^23 atoms

• 1.20 x 10^24 atoms

The mole fraction of the solute in a 1.00 molal aqueous solution is:

• 0.00177

• 0.0344

• 0.0177

• 0.1770

The mass of carbonic anhydride (CO2) formed by the complete combustion of 3.2g of carbon is:

• 8.8g

• 11.7g

• 4.4g

• 5.6g

6.02x10^20 molecules of urea are present in 100mL of its solution. The concentration of the solution is:

• 0.02M

• 0.01M

• 0.001M

• 0.1M

Concentrated nitric acid is 70% (HNO3). The amount of concentrated nitric acid solution that should be used to prepare 250 mL of 2.0 M (HNO3) would be:

• 90.0 g conc. (HNO3)

• 70.0 g conc. (HNO3)

• 54.0 g conc. (HNO3)

• 45.0 g conc. (HNO3)

1 g of magnesium is burnt with 0.56g of oxygen in a closed vessel. The left-out reactant and its quantity are (At. weight of Mg = 24, O=16):

• Mg, 0.16g

• (O2), 0.16g

• Mg, 0.44g

• (O2), 0.28g

Which of the following has the maximum number of molecules?

• 7g (N2)

• 2g (H2)

• 16g (NO2)

• 16g (O2)