Eduprobe
Question:
In which case is the number of molecules of water maximum?
0.00224 Lof water vapours at1 atmand273 K
18 mLof water
10⁻³molof water
0.18 gof water
Solution:
The maximum number of water molecules corresponds to the maximum number of moles of water. 0.00224 L of water vapours at 1 atm and 273 K corresponds to: n = PV/RT = (1 atm × 0.00224 L) / (0.08206 L atm/mol K × 273 K) = 1.07 × 10⁻⁴ mol
18 mL of water (density 1 g/mL) corresponds to: (18 mL × 1 g/mL) / 18 g/mol = 1 mol
0.18 g of water corresponds to: 0.18 g / 18 g/mol = 0.01 mol
18 mL of water has the maximum number of moles, which corresponds to the maximum number of molecules. Hence, option B is correct.