The atomic weight of helium is 4 times that of hydrogen. Its diffusion rate as compared to hydrogen will be _____________ times?

Related Mcqs:

1. What is the simplest formula of a compound containing 50% of element A (atomic weight = 10) and 50% of element B (atomic weight = 20) ?

   A. AB3
   B. A2B3
   C. A2B
   D. AB2

2. Diffusion is that property by virtue of which a perfume bottle when opened up in a room, makes the whole room fragrant with its smell. If a perfume ‘X’ diffuses twice as fast as another perfume ‘Y’; what is the molecular weight of ‘Y’, if the vapor density of gas ‘X’ is 2? Molecular weight of gas ‘X’ is to be assumed to be 2 ?

   A. 2
   B. 4
   C. 8
   D. 16

3. In the reaction, Ca + 2H2O = Ca(OH)2 + H2; what volume (c.c.) of hydrogen at STP would be liberated, when 8 gm of calcium reacts with excess water ? (Atomic weight of calcium = 40) ?

   A. 4480
   B. 2240
   C. 1120
   D. 0.4

4. If 1.5 moles of oxygen combines with aluminium to form Al2O3, then the weight of aluminium (atomic weight = 27) used in this reaction is __________ gm?

   A. 27
   B. 54
   C. 5.4
   D. 2.7

5. If pH value of an acidic solution is decreased from 5 to 2, then the increase in its hydrogen ion concentration is _____________ times?

   A. 10
   B. 100
   C. 1000
   D. 10000

6. The amount of Zn (atomic weight = 65) required to form 224 c.c. of H2 at N.T.P. on treatment with dilute H2SO4will be _____________ gm?

   A. 0.065
   B. 0.65
   C. 6.5
   D. 65

7. Referring to the periodic table of elements, it is found that with increasing atomic number. The atomic size in the same___________________?

   A. Period increases
   B. Period decreases
   C. Group increases
   D. Both ‘B’ & ‘C’

8. 1 gm mole of an alcohol whose molecular weight is 74 contains 48 gms of carbon, 10 gms of hydrogen and 16 gms of oxygen. Its molecular formula is__________________?

   A. C4H9OH
   B. C3H21OH
   C. (C2H4)2H2.OH
   D. C2H33OH

9. 6 gms of magnesium (atomic weight = 24), reacts with excess of an acid, the amount of H2 produced will be ______________ gm?

   A. 0.5
   B. 1
   C. 3
   D. 5

10. The pH value of a solution is 5.9. If the hydrogen ion concentration is decreased hundred times, the solution will be______________?

    A. Basic
    B. More acidic
    C. Neutral
    D. Of the same acidity