Question

ii) Calculate the mass of 1.51 X 1023 molecules of water.​

Answer 1

Answer:

Mass = 4.5g

Explanation:

1.51×10²³ molecules mass of H₂O = 18

Number of moles  = Number of molecules of water x Avogadro's number  

= (1.51×10²³) / (6.023×10²³) = 1/4= 0.25 mole

Number of moles =Mass / Molecular mass  

⇒ 0.25 = mass/18

Mass = 0.25×18

∴Mass = 4.5g