NEET2018ChemistrySome Basic Concepts of ChemistryActual
In which case the number of molecules of water maximum?
Options
- A0 . 00224   L of water vapours at 1   atm and 273   K .
- B0 . 18   g of water.
- C18   mL of water.
- D10 - 3 mol of water.
Correct answer
C. 18   mL of water.
Step-by-step solution
(i) 18   mL water: As d H 2 O = 1 g / mL So W H 2 O = 18 g n H 2 O = 18 18 = 1 Molecules = 1 × N A (ii) 0 . 18   g of water: n H 2 O = 0 .18 18 = 0 .01 H 2 O molecules = 0 .01 × N A (iii) ( V H 2 O   ( g ) ) STP = 0 .00224   L n H 2 O = V 22 .4 = 0 .00224 22 .4 = 0 .0001 Molecules = 0 .0001 × N A (iv) n H 2 O = 10 - 3 H 2 O molecules = 10 - 3 × N A