The number of water molecules present in a drop of water weighing 0.018 gm is 6.023 × __________?

Related Mcqs:

1. If 1 Nm3 of O2 contains ‘N’ number of molecules, then number of molecules in 2Nm3 of SO2 will be_________________?

   A. N
   B. N/2
   C. 2N
   D. 4N

2. A vessel of volume 1000 m3 contains air which is saturated with water vapour. The total pressure and temperature are 100 kPa and 20°C respectively. Assuming that the vapour pressure of water at 20°C is 2.34 kPa, the amount of water vapour (in kg) in the vessel is approximately ?

   A. 17
   B. 20
   C. 25
   D. 34

3. Assume that benzene is insoluble in water. The normal boiling points of benzene and water are 80.1 and 100°C respectively. At a pressure of 1 atm, the boiling point of a mixture of benzene and water is__________________?

   A. 80.1°C
   B. Less than 80.1°C
   C. 100°C
   D. Greater than 80.1°C but less than 100°C

4. The boiling points for pure water and pure toluene are 100°C and 110.6°C respectively. Toluene and water are completely immiscible in each other. A well agitated equimolar mixture of toluene and water are prepared. The temperature at which the above mixture will exert a pressure of one standard atm. is___________________?

   A. Less than 100°C
   B. 100°C
   C. Between 100 and 110°C
   D. 110.6°C

5. At 100°C, water and methylcyclohexane both have vapour pressures of 1 atm. Also at 100°C, the latent heats of vaporisation of these compounds are 40.63 kJ/mole for water and 31.55 kJ/mole for methylcyclohexane. The vapour pressure of water at 150°C is 4.69 atm. At 150°C, the vapour pressure of methylcyclohexane would be expected to be_________________?

   A. Significantly less than 4.69 atm
   B. Nearly equal to 4.69 atm
   C. Significantly more than 4.69 atm
   D. Indeterminate due to lack of data

6. Saturated solution of benzene in water is in equilibrium with a mixture of air and vapours of benzene and water at room temperature and pressure. Mole fraction of benzene in liquid is xB and the vapour pressures of benzene and water at these conditions are pv B and pv w respectively. The partial pressure of benzene in air-vapour mixture is_________________?

   A. PvB
   B. xB.PvB
   C. (Patm – Pvw)xB
   D. xB.Patm

7. Avogadro number is the number of molecules in one ____________ of a gas?

   A. gram
   B. Kilogram
   C. gm.mole
   D. Litre

8. Unrestrained expansion of an ideal gas does not result in its cooling due to the reason that the gas molecules ____________________?

   A. Do not lose energy on collision
   B. Are above the inversion temperature
   C. Do not exert attractive force on each other
   D. Do work equal to loss in kinetic energy

9. At a temperature of 0°K, the molecules of a gas have only _______________ energy?

   A. Rotational
   B. Vibrational
   C. Translational
   D. None of these

10. The molecules of a liquid which is in equilibrium with its vapor at its boiling point on an average have equal _____________ in the two phases?

    A. Potential energy
    B. Intermolecular forces
    C. Kinetic energy
    D. Total energy