Answer:
8.55x10^22 molecules
Explanation:
From the question given, the following data were obtained:
Density = 1g/mL
Volume = 2.56mL
Mass =?
Density = Mass /volume
Mass = Density x volume
Mass = 1 x 2.56
Mass = 2.56g
Now let us convert this mass (i.e 2.56g) of water to mole
Molar Mass of H2O = (2x1) + 16 = 2 + 16 = 18g/mol
Mass of H2O = 2.56g
Number of mole of H2O=? Number of mole = Mass /Molar Mass
Number of mole of H2O = 2.56/18
Number of mole of H2O = 0.142mol
From Avogadro's hypothesis, 1mole of any substance contains 6.02x10^23 molecules. This means that 1mole of H2O contains 6.02x10^23 molecules.
Now if 1mole of H2O contains 6.02x10^23 molecules, then 0.142mol of H2O will contain = 0.142 x 6.02x10^23 = 8.55x10^22 molecules
